Add support for GL_NV_shader_sm_builtins

Including spirv and AST tests

Also increase size of TBuiltInVariable bitfields since we've now exceeded 127
and add a static_assert to make this easier to find next time it happens!

glslang/Include/BaseTypes.h

@@ -275,6 +275,12 @@ enum TBuiltInVariable {
     EbvMeshViewIndicesNV,
 #endif
 
+    // sm builtins
+    EbvWarpsPerSM,
+    EbvSMCount,
+    EbvWarpID,
+    EbvSMID,
+
     // HLSL built-ins that live only temporarily, until they get remapped
     // to one of the above.
     EbvFragDepthGreater,
@@ -460,6 +466,11 @@ __inline const char* GetBuiltInVariableString(TBuiltInVariable v)
     case EbvMeshViewIndicesNV:          return "MeshViewIndicesNV";
 #endif
 
+    case EbvWarpsPerSM:                 return "WarpsPerSMNV";
+    case EbvSMCount:                    return "SMCountNV";
+    case EbvWarpID:                     return "WarpIDNV";
+    case EbvSMID:                       return "SMIDNV";
+
     default:                      return "unknown built-in variable";
     }
 }