[clang] [clang][modules] HeaderSearch::MarkFileModuleHeader sets textual headers' HeaderFileInfo non-external when it shouldn't (PR #89005)

[Ian Anderson via cfe-commits]

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@@ -1313,11 +1313,19 @@ OptionalFileEntryRef HeaderSearch::LookupSubframeworkHeader(
 // File Info Management.
 //===----------------------------------------------------------------------===//
 
+static bool moduleMembershipNeedsMerge(const HeaderFileInfo *HFI,
+                                       ModuleMap::ModuleHeaderRole Role) {
+  if (ModuleMap::isModular(Role))
+    return !HFI->isModuleHeader || HFI->isTextualModuleHeader;
+  else if (!HFI->isModuleHeader && (Role & ModuleMap::TextualHeader))
+    return !HFI->isTextualModuleHeader;
+  else
+    return false;
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ian-twilightcoder wrote:

HFI doesn't have == declared, and I'm not sure it's worth adding one for this?

https://github.com/llvm/llvm-project/pull/89005