Revert "[OMPIRBuilder] Don't use invalid debug loc in task proxy function." (#148728)

There is a sanitizer fail in CI after this which I need to investigate.
Reverting for now.
Reverts #148284

Author: abidh

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

@@ -7229,11 +7229,9 @@ static Function *emitTargetTaskProxyFunction(
 
   bool HasShareds = SharedArgsOperandNo > 0;
   bool HasOffloadingArrays = NumOffloadingArrays > 0;
-  IRBuilder<>::InsertPointGuard IPG(Builder);
   BasicBlock *EntryBB =
       BasicBlock::Create(Builder.getContext(), "entry", ProxyFn);
   Builder.SetInsertPoint(EntryBB);
-  Builder.SetCurrentDebugLocation(llvm::DebugLoc());
 
   SmallVector<Value *> KernelLaunchArgs;
   KernelLaunchArgs.reserve(StaleCI->arg_size());