[hip] Remove the coercion on aggregate kernel arguments.
- If an aggregate argument is indirectly accessed within kernels, direct passing results in unpromotable alloca, which degrade performance significantly. InferAddrSpace pass is enhanced in D91121 to take the assumption that generic pointers loaded from the constant memory could be regarded global ones. The need for the coercion on aggregate arguments is mitigated.
Differential Revision: https://reviews.llvm.org/D89980