meson: Enable graw tests on mingw

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Acked-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18016>

src/gallium/tests/meson.build

@@ -26,8 +26,4 @@ if with_gallium_softpipe
   subdir('unit')
 endif
 
-if host_machine.system() != 'windows' or cpp.get_id() != 'gcc'
-  # FIXME: This has linking errors I can't figure out with MinGW. works fine
-  # with MSVC, works fine with GCC on Linux.
-  subdir('graw')
-endif
+subdir('graw')