clang archiver tool is llvm-ar on Windows and ar on other platforms.
MinGW always uses ar. Replace shell script (Unix-only) that calls ar
with a Python script (OS-independent) that calls an appropriate archiver
tool selected at configuration time. Move the logic not to generate
empty sources into pmdinfogen.
Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
e6e9730c70