[glslang][extension] GL_ARB_geometry_shader4.

[ShchchowAMD]

Support extension GL_ARB_geometry_shader4.

1. primitive type and vertices number would be determined in link time, hence set flags.
2. Some array related changes in ParseHelper have dependency on implicit array size set.
3. For some special var like gl_VerticesIn, its attributes would be depend on api-set topology and extra info across stages.

[ShchchowAMD]

Dependency PR: https://github.com/KhronosGroup/glslang/pull/3074

[ShchchowAMD]

Update: may pending for a which as introducing new legacy check functions here, leading to too many test results changes, would double check.

[arcady-lunarg]

@ShchchowAMD do you plan to move this forward at some point?