[clang] [clang][modules] Remove preloaded SLocEntries from PCM files (PR #66962)

[Ben Langmuir via cfe-commits]

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@@ -2082,6 +2082,11 @@ std::pair<bool, bool> SourceManager::isInTheSameTranslationUnit(
   if (LOffs.first == ROffs.first)
     return std::make_pair(true, LOffs.second < ROffs.second);
 
+  // Built-ins are not considered part of any TU.
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benlangmuir wrote:

Does this have to come before `getInBeforeInTUCache`? I'm wondering if it is possible and profitable to sink this off the hot path.

https://github.com/llvm/llvm-project/pull/66962