bpo-45548: Put Modules/Setup extensions into builddir

[tiran]

Modules/Setup used to put shared extensions into ./Modules/
directory. Now it puts the shared extensions in the same directory
library directory ./build/lib.$plat-$ver as distutils.

The change makes the shared modules importable and fixes build issues.

Signed-off-by: Christian Heimes [email protected]

https://bugs.python.org/issue45548

[tiran]

Modules/Setup

*shared*
cmath cmathmodule.c _math.c
math mathmodule.c _math.c

without fix

$ make
*** WARNING: renaming "_zoneinfo" since importing it failed: PyCapsule_Import could not import module "datetime"
*** WARNING: renaming "_asyncio" since importing it failed: No module named 'math'

The following modules found by detect_modules() in setup.py, have been
built by the Makefile instead, as configured by the Setup files:
_abc                  cmath                 math               
pwd                   time                                     


Following modules built successfully but were removed because they could not be imported:
_asyncio              _zoneinfo          

$ ./python -c "import math"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ModuleNotFoundError: No module named 'math'

$ find -name '*math*.so'
./Modules/math.cpython-311-x86_64-linux-gnu.so
./Modules/cmath.cpython-311-x86_64-linux-gnu.so

with fix

$ make
...
The following modules found by detect_modules() in setup.py, have been
built by the Makefile instead, as configured by the Setup files:
_abc                  cmath                 math               
pwd                   time    

$ ./python -c "import math"
$ echo $?
0

$ find -name '*math*.so'
./build/lib.linux-x86_64-3.11/math.cpython-311-x86_64-linux-gnu.so
./build/lib.linux-x86_64-3.11/cmath.cpython-311-x86_64-linux-gnu.so

[brettcannon]

If this leaves draft and my review is still desired, please feel free to add me back.

[tiran]

I have landed the fix with another commit.