[llvm] [AMDGPU] Add make.buffer.rsrc to InferAddressSpaces (PR #140770)

[Matt Arsenault via llvm-commits]

================
@@ -192,13 +192,29 @@ define amdgpu_kernel void @load_to_lds_fat_pointer_as_flat(ptr addrspace(7) %buf
   ret void
 }
 
+define amdgpu_kernel void @make_buffer_rsrc_global_as_flat(ptr addrspace(1) %global, i32 %extent) {
+  ;; NOTE: flags value not representative of real input
+; CHECK-LABEL: define amdgpu_kernel void @make_buffer_rsrc_global_as_flat(
+; CHECK-SAME: ptr addrspace(1) [[GLOBAL:%.*]], i32 [[EXTENT:%.*]]) {
+; CHECK-NEXT:    [[BUFFER_FAT_PTR:%.*]] = call ptr addrspace(7) @llvm.amdgcn.make.buffer.rsrc.p7.p1(ptr addrspace(1) [[GLOBAL]], i16 0, i32 [[EXTENT]], i32 0)
+; CHECK-NEXT:    store i32 [[EXTENT]], ptr addrspace(7) [[BUFFER_FAT_PTR]], align 4
+; CHECK-NEXT:    ret void
+;
+  %cast = addrspacecast ptr addrspace(1) %global to ptr
+  %buffer.fat.ptr = call ptr addrspace(7) @llvm.amdgcn.make.buffer.rsrc.p7.p9(ptr %cast, i16 0, i32 %extent, i32 0)
----------------
arsenm wrote:

```suggestion
  %buffer.fat.ptr = call ptr addrspace(7) @llvm.amdgcn.make.buffer.rsrc.p7.p0(ptr %cast, i16 0, i32 %extent, i32 0)
```

https://github.com/llvm/llvm-project/pull/140770