[clang] [llvm] [mlir] [Clang][CodeGen] Start migrating away from assuming the Default AS is 0 (PR #88182)

[Yaxun Liu via cfe-commits]

================
@@ -368,7 +368,8 @@ CodeGenModule::CodeGenModule(ASTContext &C,
   IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
   IntPtrTy = llvm::IntegerType::get(LLVMContext,
     C.getTargetInfo().getMaxPointerWidth());
-  Int8PtrTy = llvm::PointerType::get(LLVMContext, 0);
+  Int8PtrTy = llvm::PointerType::get(LLVMContext,
----------------
yxsamliu wrote:

Fixing emitUsed probably is a feasible solution, but GlobalsInt8PtrTy will cause the used array containing pointers to addr space 1, which is not backward compatible for HIP. Maybe just use pointer to addr space 0 type as before.

https://github.com/llvm/llvm-project/pull/88182