vkd3d-shader/hlsl: Store parsed values in hlsl_ir_compile().

Makes emitting shaders from fx.c easier, and brings parsing failures
upfront.

Non-effect target profiles don't perform any type checks on
ConstructGSWithSO(), nor use shader objects in any way, but they do
check if the argument count is correct.

So we create a GeometryShader object with NULL decl and profile when
targeting non-effect profiles, so our type checks still work and
implicit conversions aren't attempted.

tests/hlsl/constructgswithso.shader_test

@@ -1,4 +1,4 @@
-[pixel shader todo]
+[pixel shader]
 float4 main() : sv_target { return 0; }
 
 GeometryShader gs1 = CompileShader(gs_5_0, main());