[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
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arsenm wrote:

Not sure this negative check really works as expected; won't any global variable be printed at the top of the file before any functions?

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