[clang] [clang][modules] Move `SLocEntry` search into `ASTReader` (PR #66966)

[Ben Langmuir via cfe-commits]

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@@ -864,74 +864,7 @@ FileID SourceManager::getFileIDLocal(SourceLocation::UIntTy SLocOffset) const {
 /// This function knows that the SourceLocation is in a loaded buffer, not a
 /// local one.
 FileID SourceManager::getFileIDLoaded(SourceLocation::UIntTy SLocOffset) const {
-  if (SLocOffset < CurrentLoadedOffset) {
-    assert(0 && "Invalid SLocOffset or bad function choice");
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benlangmuir wrote:

Where would this case end up failing in the new implementation?

https://github.com/llvm/llvm-project/pull/66966