https://bugs.gentoo.org/945373

media-libs/mesa became incompatible with media-libs/mesa-amber.
The best way to deal with this seems to be to rename mesa-amber
libraries and install them alongside.

This patch renames libgbm.so to libgbm-amber.so and libglapi.so to
libglapi-amber.so, so mesa-amber drivers can use their own libraries.

--- a/src/gbm/meson.build
+++ b/src/gbm/meson.build
@@ -45,8 +45,10 @@ if with_platform_wayland
   incs_gbm += inc_wayland_drm
 endif
 
+gbm_lib_name = 'gbm_@0@'.format(glvnd_vendor_name)
+
 libgbm = shared_library(
-  'gbm',
+  gbm_lib_name,
   files_gbm,
   include_directories : incs_gbm,
   c_args : [args_gbm],
--- a/src/mapi/shared-glapi/meson.build
+++ b/src/mapi/shared-glapi/meson.build
@@ -41,8 +41,10 @@ if with_platform_windows
   _glapi_c_args += ['-D_GLAPI_DLL_EXPORTS']
 endif
 
+glapi_lib_name = 'glapi_@0@'.format(glvnd_vendor_name)
+
 libglapi = shared_library(
-  'glapi',
+  glapi_lib_name,
   [files_mapi_glapi, files_mapi_util, shared_glapi_mapi_tmp_h],
   c_args : [
     _glapi_c_args,