Parameters of spirv_decorate_id should accept variables

spirv_decorate_id will generate OpDecorateId. The parameter list should
accept variables as part of decorations. This is because OpDecorateId
allows this. The spec says:

  All such <id> Extra Operands must be constant instructions or
  OpVariable instructions.

Test/spv.intrinsicsSpirvDecorateId.comp

@@ -0,0 +1,16 @@
+#version 460 core
+#extension GL_EXT_spirv_intrinsics: enable
+
+layout(local_size_x = 1) in;
+
+layout(binding = 1) uniform CounterBuffer {
+  uint counter;
+} x;
+
+layout(binding = 0) spirv_decorate_id(extensions = ["SPV_GOOGLE_hlsl_functionality1"], 5634, x) uniform Uniform {
+  uint y;
+};
+
+void main()
+{
+}