-Add a new define to wrap the output semantic that we want to be post declare as precise.
-Modify DXC-SIRV to add the NoContraction decorator on precise output semantics.
-Modify spirv_glsl to post declare as precise output semantics
-Example: out precise float4 gl_positon; will add precise gl_position; post declaration.
[REVIEW] [at]laura.hermanns
[CL 29338529 by serge bernier in ue5-main branch]
This represents UE4/Main @17911760, Release-5.0 @17915875 and Dev-PerfTest @17914035
[CL 17918595 by aurel cordonnier in ue5-release-engine-test branch]