SPV: Implement Vulkan version of GLSL (KHR_vulkan_glsl).

Test/vulkan.comp

@@ -0,0 +1,12 @@
+#version 450
+
+layout(local_size_x_id = 18, local_size_z_id = 19) in;
+layout(local_size_x = 32, local_size_y = 32) in;
+layout(local_size_z_id = 14) in;  // ERROR, can't change this
+
+void main()
+{
+    gl_WorkGroupSize;
+}
+
+layout(local_size_y_id = 19) in; // ERROR, already used: TODO not yet reported