[clang] [clang] Fix `gnu::init_priority` attribute handling for reserved values (PR #121577)

[Erich Keane via cfe-commits]

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@@ -3644,16 +3644,20 @@ static void handleInitPriorityAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
     return;
   }
 
-  // Only perform the priority check if the attribute is outside of a system
-  // header. Values <= 100 are reserved for the implementation, and libc++
-  // benefits from being able to specify values in that range.
-  if ((prioritynum < 101 || prioritynum > 65535) &&
-      !S.getSourceManager().isInSystemHeader(AL.getLoc())) {
+  if (prioritynum > 65535) {
     S.Diag(AL.getLoc(), diag::err_attribute_argument_out_of_range)
-        << E->getSourceRange() << AL << 101 << 65535;
+        << E->getSourceRange() << AL << 0 << 65535;
     AL.setInvalid();
     return;
   }
+
+  // Only perform the priority check if the attribute is outside of a system
+  // header. Values <= 100 are reserved for the implementation, and libc++
+  // benefits from being able to specify values in that range.
+  if (prioritynum < 101) {
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erichkeane wrote:

We don't use curleys per coding standard for single statement 'if' blocks, so please remove them.

https://github.com/llvm/llvm-project/pull/121577