[clang] [LifetimeSafety] Add missing origins stats for lifetime analysis (PR #166568)

[Utkarsh Saxena via cfe-commits]

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@@ -34,6 +38,12 @@ enum class Confidence : uint8_t {
   Definite // Reported as a definite error (-Wlifetime-safety-permissive)
 };
 
+/// A structure to hold the statistics related to LifetimeAnalysis.
+/// Curently it holds only the missing origin details.
+struct LifetimeSafetyStats {
+  llvm::StringMap<unsigned> MissingOriginCount;
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usx95 wrote:

Can you add comment about this.

Example: Tracks expressions and their counts that do not get associated to an Origin after the end of the analysis.

https://github.com/llvm/llvm-project/pull/166568