8129b6b53b
The change improves the code in general and, as a side effect, avoids crashing on an impossible address space casts guarded by `__isGlobal/__isShared`, which partially fixes https://github.com/llvm/llvm-project/issues/112760 It's still possible to trigger the issue by using explicit AS casts w/o AS checks, but LLVM should no longer crash on valid code. This is #112964 + a small fix for the crash on unintended argument access which was the root cause to revers the earlier version of the patch.