Merge pull request #2700 from ZhiqianXia/u2i

Support Uint to Int implicit conversions at #extension GL_ARB_gpu_shader5.

gtests/AST.FromFile.cpp

@@ -282,6 +282,7 @@ INSTANTIATE_TEST_SUITE_P(
         "terminate.vert",
         "negativeWorkGroupSize.comp",
         "textureoffset_sampler2darrayshadow.vert",
+        "GL_ARB_gpu_shader5.u2i.vert",
     })),
     FileNameAsCustomTestSuffix
 );