[llvm] [Coverage] Move SingleByteCoverage out of CountedRegion (PR #110966)

[Ellis Hoag via llvm-commits]

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@@ -1424,7 +1429,8 @@ CoverageData CoverageMapping::getCoverageForFile(StringRef Filename) const {
   }
 
   LLVM_DEBUG(dbgs() << "Emitting segments for file: " << Filename << "\n");
-  FileCoverage.Segments = SegmentBuilder::buildSegments(Regions);
+  FileCoverage.Segments =
+      SegmentBuilder::buildSegments(Regions, *SingleByteCoverage);
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ellishg wrote:

This will crash if `RecordIndices` is empty. Is that possible? If not, can we add an assert?

https://github.com/llvm/llvm-project/pull/110966