[Clang][OpenMP][OMPBuilder] Moving OMP allocation and cache creation code to OMPBuilderCBHelpers

[fghanim]

Summary

Modified the OMPBuilderCBHelpers in the following ways:

• Moved location of class definition and deleted all constructors
• Moved OpenMP-specific address allocation of local variables
• Moved threadprivate variable creation for the current thread

[jdoerfert]

clang/lib/CodeGen/CGStmtOpenMP.cpp

882

Is this needed?

clang/lib/CodeGen/CodeGenFunction.h

1594

Nit: Make it a doxygen comment with 3x`/, -will` + full stop.

1606

Nit: No need.

1626

What is wrong with BB->getFirstNonPHIOrDbgOrLifetime()? If it is to avoid too many test changes, please add a TODO. I think from a functional perspective there is no need to advance it after the first set of allocas that may be separated from the phis by non-allocas?

[fghanim]

clang/lib/CodeGen/CGStmtOpenMP.cpp

882

All these are changes that I forgot to remove after I created a special version for EmitOMPFirstprivateClause in D79677 for the OMPBuilder

clang/lib/CodeGen/CodeGenFunction.h

1626

Nothing wrong with it. The first while loop, I just came across a case that I don't remember at the moment that had an instruction that wasn't an alloca, and I wanted to skip over that.
the second while, is to get to the first non-alloca instruction. The purpose is to be able to insert new allocas, after already generated allocas.

[fghanim]

updating in response to review comments

[jdoerfert]

Interesting that no tests changed but I guess we just start the move to the IRBUilder.

I think there are two minor comments from before that need to be addressed and the alloca thing, otherwise LGTM.

clang/lib/CodeGen/CodeGenFunction.h

1626

There is no need to do that. It is fine to insert allocas anywhere in the block.

[fghanim]

• rebase
• addressing reviewer's comments