llvm13: lang/python/3.8 build failure

lang/python/3.8 fails to build with llvm13. The reason appears to be
some silly confusion between "openbsd7" and "openbsd7.0" in the build
system:

---------------------------->
LD_LIBRARY_PATH=/usr/obj/Python-3.8.12/Python-3.8.12 CC='cc -pthread' LDSHARED='cc -pthread -shared -fPIC -L/usr/local/lib/ -L/usr/obj/Python-3.8.12/Python-3.8.12 -L/usr/local/lib/ ' OPT='-DNDEBUG -O2 -pipe -g -fPIC' _TCLTK_INCLUDES='' _TCLTK_LIBS='' ./python -E ./setup.py build
Traceback (most recent call last):
File "./setup.py", line 2319, in <module>
class PyBuildInstallLib(install_lib):
File "./setup.py", line 2326, in PyBuildInstallLib
shlib_suffix = sysconfig.get_config_var("SHLIB_SUFFIX")
File "/usr/obj/Python-3.8.12/Python-3.8.12/Lib/sysconfig.py", line 615, in get_config_var
return get_config_vars().get(name)
File "/usr/obj/Python-3.8.12/Python-3.8.12/Lib/sysconfig.py", line 564, in get_config_vars
_init_posix(_CONFIG_VARS)
File "/usr/obj/Python-3.8.12/Python-3.8.12/Lib/sysconfig.py", line 432, in _init_posix
_temp = __import__(name, globals(), locals(), ['build_time_vars'], 0)
ModuleNotFoundError: No module named '_sysconfigdata__openbsd7_amd64-unknown-openbsd7'
<----------------------------

Note that "_sysconfigdata__openbsd7_amd64-unknown-openbsd7.0.py" exists.

The trigger appears to be the new support for "cc --print-multiarch":

llvm 12 says on stderr:
cc: error: unsupported option '--print-multiarch'
cc: error: no input files

llvm 13 says on stdout:
amd64-unknown-openbsd7.0

I haven't managed to trace this any further.

--
Christian "naddy" Weisgerber naddy@mips.inka.de