add --deep flag to dub build

[rtbo]

Allows to build all dependencies of a static library.

This provides the same functionality as the dub-build-deep package.
The difference is that all dependencies are built in the same DUB invocation, which imply that the build will be fully compatible with dub describe.

E.g.
dub describe vibe-d:http will describe the build settings of all dependencies of vibe-d:http and dub build --deep vibe-d:http will build all dependencies with the exact same build settings.
If we build dependencies one by one (as done by dub-build-deep), some settings will differ.

See also #2644

Fixes #2224 (and possibly #2209)

[github-actions]

✅ PR OK, no changes in deprecations or warnings

Total deprecations: 14

Total warnings: 0

Build statistics:

 statistics (-before, +after)
 executable size=5272064 bin/dub
 rough build time=90s

Full build output

DUB version 1.32.1, built on Jul 23 2023
LDC - the LLVM D compiler (1.33.0):
  based on DMD v2.103.1 and LLVM 15.0.7
  built with LDC - the LLVM D compiler (1.33.0)
  Default target: x86_64-unknown-linux-gnu
  Host CPU: skylake-avx512
  http://dlang.org - http://wiki.dlang.org/LDC

  Registered Targets:
    aarch64    - AArch64 (little endian)
    aarch64_32 - AArch64 (little endian ILP32)
    aarch64_be - AArch64 (big endian)
    amdgcn     - AMD GCN GPUs
    arm        - ARM
    arm64      - ARM64 (little endian)
    arm64_32   - ARM64 (little endian ILP32)
    armeb      - ARM (big endian)
    avr        - Atmel AVR Microcontroller
    bpf        - BPF (host endian)
    bpfeb      - BPF (big endian)
    bpfel      - BPF (little endian)
    hexagon    - Hexagon
    lanai      - Lanai
    mips       - MIPS (32-bit big endian)
    mips64     - MIPS (64-bit big endian)
    mips64el   - MIPS (64-bit little endian)
    mipsel     - MIPS (32-bit little endian)
    msp430     - MSP430 [experimental]
    nvptx      - NVIDIA PTX 32-bit
    nvptx64    - NVIDIA PTX 64-bit
    ppc32      - PowerPC 32
    ppc32le    - PowerPC 32 LE
    ppc64      - PowerPC 64
    ppc64le    - PowerPC 64 LE
    r600       - AMD GPUs HD2XXX-HD6XXX
    riscv32    - 32-bit RISC-V
    riscv64    - 64-bit RISC-V
    sparc      - Sparc
    sparcel    - Sparc LE
    sparcv9    - Sparc V9
    systemz    - SystemZ
    thumb      - Thumb
    thumbeb    - Thumb (big endian)
    ve         - VE
    wasm32     - WebAssembly 32-bit
    wasm64     - WebAssembly 64-bit
    x86        - 32-bit X86: Pentium-Pro and above
    x86-64     - 64-bit X86: EM64T and AMD64
    xcore      - XCore
   Upgrading project in /home/runner/work/dub/dub/
    Starting Performing "release" build using /opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/ldc2 for x86_64.
    Building dub 1.34.0+commit.12.ga880cc92: building configuration [application]
source/dub/dependency.d(917,18): Deprecation: scope variable `this` assigned to non-scope parameter `oth` calling `opEquals`
source/dub/dependency.d(920,30): Deprecation: scope variable `this` assigned to non-scope parameter `a` calling `doCmp`
source/dub/dependency.d(921,27): Deprecation: scope variable `this` assigned to non-scope parameter `b` calling `doCmp`
source/dub/dependency.d(939,26): Deprecation: scope variable `this` assigned to non-scope parameter `oth` calling `opEquals`
source/dub/internal/configy/Exceptions.d(130,34): Deprecation: reference to local variable `buffer` assigned to non-scope anonymous parameter
source/dub/internal/configy/Exceptions.d(134,34): Deprecation: reference to local variable `buffer` assigned to non-scope anonymous parameter
source/dub/internal/configy/Exceptions.d(248,27): Deprecation: `@safe` function `formatMessage` calling `formattedWrite`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/write.d(537,34):        which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        which would be `@system` because of:
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        scope variable `this` assigned to non-scope parameter `e` calling `put`
source/dub/internal/configy/Exceptions.d(250,27): Deprecation: `@safe` function `formatMessage` calling `formattedWrite`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/write.d(537,34):        which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        which would be `@system` because of:
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        scope variable `this` assigned to non-scope parameter `e` calling `put`
source/dub/internal/configy/Exceptions.d(283,27): Deprecation: `@safe` function `formatMessage` calling `formattedWrite`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/write.d(537,34):        which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        which would be `@system` because of:
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        scope variable `this` assigned to non-scope parameter `e` calling `put`
source/dub/internal/configy/Exceptions.d(286,27): Deprecation: `@safe` function `formatMessage` calling `formattedWrite`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/write.d(537,34):        which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        which would be `@system` because of:
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        scope variable `this` assigned to non-scope parameter `e` calling `put`
source/dub/internal/configy/Exceptions.d(323,31): Deprecation: `@safe` function `formatMessage` calling `formattedWrite`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/write.d(537,34):        which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        which would be `@system` because of:
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        scope variable `this` assigned to non-scope parameter `e` calling `put`
source/dub/internal/configy/Exceptions.d(325,31): Deprecation: `@safe` function `formatMessage` calling `formattedWrite`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/write.d(537,34):        which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        which would be `@system` because of:
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        scope variable `this` assigned to non-scope parameter `e` calling `put`
source/dub/internal/configy/Exceptions.d(332,31): Deprecation: `@safe` function `formatMessage` calling `formattedWrite`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/write.d(537,34):        which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        which would be `@system` because of:
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        scope variable `this` assigned to non-scope parameter `e` calling `put`
source/dub/internal/configy/Exceptions.d(335,31): Deprecation: `@safe` function `formatMessage` calling `formattedWrite`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/write.d(537,34):        which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec`
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        which would be `@system` because of:
/opt/hostedtoolcache/dc/ldc2-1.33.0/x64/ldc2-1.33.0-linux-x86_64/bin/../import/std/format/spec.d(258,33):        scope variable `this` assigned to non-scope parameter `e` calling `put`
     Linking dub
STAT:statistics (-before, +after)
STAT:executable size=5272064 bin/dub
STAT:rough build time=90s

[MrcSnm]

@rtbo So far, the only thing I see missing is a test. Add a test using the --deep flag
I'm also really looking for that since I have been using quite a hack for my engine

[MrcSnm]

LGTM @WebFreak001 @Geod24

[MrcSnm]

@rtbo I have wrote this file here:

---

Added --deep= switch to dub build

By specifying this flag, you can now build all the dependencies
of a staticLibrary. The default behavior is to only build the
library located in the root directory of the dub configuration
file. This allows better integration with other build systems
which require the libraries to be built upfront.

dub build --deep

If a staticLibrary A depends on staticLibrary B, and the --deep
flag is specified, dub will output both the A and B libraries.

---

Feel free to modify as you see fit. This is a required file which goes inside the changelog folder.

[MrcSnm]

Hey there @WebFreak001 @Geod24 can you take a look into this PR?