[clang] [CUDA][HIP] Exclude external variables from constant promotion. (PR #73549)

[Matt Arsenault via cfe-commits]

================
@@ -104,3 +106,17 @@ void fun() {
   (void) b<double>;
   (void) var_host_only;
 }
+
+// NEG-NOT: external_func
+extern __global__ void external_func();
+// NEG-NOT: @external_dep
+extern void* const external_dep[] = {
+  (void*)(external_func)
+};
+// NEG-NOT: @external_arr
----------------
arsenm wrote:

I mean negative checks are inherently fragile, and the place you are checking it does not exist isn't where globals are printed. An -implicit-check-not=xxx argument to FIleCheck would be more thorough 

https://github.com/llvm/llvm-project/pull/73549