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!

Test/glsl.450.subgroup.tese

@@ -230,3 +230,24 @@ void partitioned_works(vec4 f4)
   subgroupPartitionedExclusiveOrNV(ballot, parti);
   subgroupPartitionedExclusiveXorNV(ballot, parti);
 }
+
+// tests for NV_shader_sm_builtins
+void sm_builtins_err()
+{
+    gl_WarpsPerSMNV;    // ERROR, no extension
+    gl_SMCountNV;       // ERROR, no extension
+    gl_WarpIDNV;        // ERROR, no extension
+    gl_SMIDNV;          // ERROR, no extension
+}
+
+#ifdef GL_NV_shader_sm_builtins
+#extension GL_NV_shader_sm_builtins : enable
+#endif
+
+void sm_builtins()
+{
+    gl_WarpsPerSMNV;
+    gl_SMCountNV;
+    gl_WarpIDNV;
+    gl_SMIDNV;
+}