Add ES 320 support and additional error checks for SPV_NV_mesh_shader

- Add ES 320 support
- Error out use of perprimitiveNV for non mesh/fragment shaders
- Error out use of mesh/task shaders w/o use of NV_mesh_shader
- Error out use of NV_mesh_shader for non task/mesh shaders
- Error out use of perviewNV for non mesh shaders
- Error out use of taskNV for non mesh/task shaders
- Add test case for mesh shader with ES 320 profile

glslang/MachineIndependent/parseVersions.h

@@ -103,6 +103,9 @@ public:
     virtual void requireSpv(const TSourceLoc&, const char* op);
     virtual bool checkExtensionsRequested(const TSourceLoc&, int numExtensions, const char* const extensions[], const char* featureDesc);
     virtual void updateExtensionBehavior(const char* const extension, TExtensionBehavior);
+#ifdef NV_EXTENSIONS
+    virtual bool validateExtensionName(const TSourceLoc&, const char* const extension);
+#endif
 
     virtual void C_DECL error(const TSourceLoc&, const char* szReason, const char* szToken,
         const char* szExtraInfoFormat, ...) = 0;