[clang] [Coverage][Expansion] handle nested macros in scratch space (PR #89869)

[NAKAMURA Takumi via cfe-commits]

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@@ -298,6 +298,22 @@ class CoverageMappingBuilder {
                            : SM.getIncludeLoc(SM.getFileID(Loc));
   }
 
+  /// Find out where the current file is included or macro is expanded. If the
+  /// found expansion is a <scratch space>, keep looking.
+  SourceLocation getIncludeOrNonScratchExpansionLoc(SourceLocation Loc) {
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chapuni wrote:

This may be integrated to `getIncludeOrExpansionLoc(FoldScratch=true)` as an optional behavior.

https://github.com/llvm/llvm-project/pull/89869