Fix build with --with-included-glib on Darwin

[Adam Mercer]

On Sun, Nov 8, 2015 at 8:33 AM, Rudá Moura <ruda.moura at gmail.com> wrote:
> This proposed patch correctly build pkg-config with option
> --with-included-glib enabled on Darwin.
>
> Darwin (OS X) requires Carbon and CoreFoundation frameworks linked,
> otherwise
> there will be missing symbols:
>
> Undefined symbols for architecture x86_64:
>   "_CFRelease", referenced from:
>       _find_folder in libglib-2.0.a(libglib_2_0_la-gutils.o)
>   "_CFStringGetCString", referenced from:
>       _find_folder in libglib-2.0.a(libglib_2_0_la-gutils.o)
>   "_CFStringGetCStringPtr", referenced from:
>       _find_folder in libglib-2.0.a(libglib_2_0_la-gutils.o)
>   "_CFStringGetLength", referenced from:
>       _find_folder in libglib-2.0.a(libglib_2_0_la-gutils.o)
>   "_CFURLCopyFileSystemPath", referenced from:
>       _find_folder in libglib-2.0.a(libglib_2_0_la-gutils.o)
>   "_CFURLCreateFromFSRef", referenced from:
>       _find_folder in libglib-2.0.a(libglib_2_0_la-gutils.o)
>   "_FSFindFolder", referenced from:
>       _find_folder in libglib-2.0.a(libglib_2_0_la-gutils.o)
>   "_kCFAllocatorSystemDefault", referenced from:
>       _find_folder in libglib-2.0.a(libglib_2_0_la-gutils.o

Just ran into this issue myself and this patch fixed it for me.

Cheers

Adam