Bug 1363655 - part 4 - remove bindgen_enabled key from namespace returned from stylo; r=rillian

We can get this information directly from --enable-stylo-build-bindgen.

toolkit/moz.configure

@@ -776,7 +776,6 @@ def stylo(stylo_config, bindgen_config_paths, bindgen_enabled):
     return namespace(
         libclang_path=bindgen_config_paths.libclang_path,
         clang_path=bindgen_config_paths.clang_path,
-        bindgen_enabled=bool(bindgen_enabled),
     )
 
 set_config('MOZ_STYLO', stylo_config.build)
@@ -786,7 +785,7 @@ set_define('MOZ_STYLO_ENABLE', stylo_config.enable)
 
 set_config('MOZ_LIBCLANG_PATH', stylo.libclang_path)
 set_config('MOZ_CLANG_PATH', stylo.clang_path)
-set_config('MOZ_STYLO_BINDGEN', stylo.bindgen_enabled)
+set_config('MOZ_STYLO_BINDGEN', depends_if('--enable-stylo-build-bindgen')(lambda _: True))
 
 option('--with-servo', env='SERVO_TARGET_DIR', nargs=1,
        help='Absolute path of the target directory where libgeckoservo can '