[HLSL] Validate system value semantic based on the entry profile instead of shader profile

[python3kgae]

When report diag::err_hlsl_attr_unsupported_in_stage, the validation for system value semantic is checking shader profile.
But it is OK for a shader to have both pixel entry and compute entry at the same time.
Need to validate system value semantic based on the profile of the entry function.

[bogner]

Fixed in ef2b170