Can't compile core for msp430 in release mode

[japaric]

$ rustup default nightly-2017-11-04

$ rustup component add rust-src

$ cp -r $(rustc --print sysroot)/lib/rustlib/src/rust/src .

$ cd src/libcore

$ cargo build --target msp430-none-elf --release
   Compiling core v0.0.0 (file:///home/japaric/tmp/src/libcore)
error: linking with `msp430-elf-gcc` failed: exit code: 1
  |
  = note: "msp430-elf-gcc" "-mcpu=msp430" "-c" "-o" "/home/japaric/tmp/src/libcore/target/msp430-none-elf/release/deps/core-610eca78cd1149b2.o" "/home/japaric/tmp/src/libcore/target/msp430-none-elf/release/deps/core-610eca78cd1149b2.s"
  = note: msp430-elf-gcc: error: /home/japaric/tmp/src/libcore/target/msp430-none-elf/release/deps/core-610eca78cd1149b2.s: No such file or directory
          msp430-elf-gcc: fatal error: no input files
          compilation terminated.


error: aborting due to previous error

error: Could not compile `core`.

$ ls target/msp430-none-elf/release/deps
core-610eca78cd1149b2.core0.rust-cgu.bytecode.encoded  core-610eca78cd1149b2.core0.rust-cgu.s  core-610eca78cd1149b2.crate.metadata.rust-cgu.o  core-610eca78cd1149b2.d

cc @alexcrichton seems related to the thinLTO / codegen-unit changes. Seems like the name of the intermediate .s artifact changed but the "external assembler" logic wasn't updated to match the new name.

[alexcrichton]

Heh yeah I'd definitely beleive that! Anything related to the "don't use the integrated assembler" breaks all the time...