[Flang][OpenMP] Additional global address space modifications for device

A prior PR added a portion of the global address space modifications required for declare target to, this PR seeks to add a small amount more leftover from that PR.

The intent is to allow for more correct IR that the backends (in particular AMDGPU) can treat more aptly for optimisations and code correctness

1/3 required PRs to enable declare target to mapping, should look at PR 3/3 to check for full green passes (this one will fail a number due to some dependencies).

Co-authored-by: Raghu Maddhipatla [email protected]

Author: agozillon

flang/include/flang/Optimizer/Builder/FIRBuilder.h

@@ -954,6 +954,10 @@ mlir::Value genLifetimeStart(mlir::OpBuilder &builder, mlir::Location loc,
 void genLifetimeEnd(mlir::OpBuilder &builder, mlir::Location loc,
                     mlir::Value mem);
 
+uint64_t getGlobalAddressSpace(mlir::DataLayout *dataLayout);
+
+uint64_t getProgramAddressSpace(mlir::DataLayout *dataLayout);
+
 } // namespace fir::factory
 
 #endif // FORTRAN_OPTIMIZER_BUILDER_FIRBUILDER_H