[build2] pkg-config file name

[Boris Kolpackov]

Boris Kolpackov <boris at codesynthesis.com> writes:

> Paul Stath <PStath at jmawireless.com> writes:
> 
> > Generate a symlink to the generated  *.{shared,static}.pc file.
> > The symlink target is determined by the value of config.bin.exe.lib variable.
> 
> Yes, if you are keen to try/use it, I will take a stab at it tomorrow.
> Shouldn't be anything complicated (famous last words).

Ok, I've looked into it and I think we can do even better than the
symlink: we can generate a common .pc file by ignoring any static/shared-
specific poptions and splitting loptions/libs into Libs/Libs.private.

It will be "best effort", in a sense that it's not guaranteed to be
sufficient in all cases, but it will probably cover the majority of
cases, even on Windows, thanks to auto-dllimport.

I have it mostly working but need to figure one last tricky bit (has to
do with cases when only one of the static/shared libraries is installed).
Hopefully I will have something for you to try by tomorrow.