[clang] [clang][Tooling] Reuse standard-library symbol descriptors (PR #202663)

[David Zbarsky via cfe-commits]

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@@ -24,6 +24,12 @@ namespace {
 // Symbol name -> Symbol::ID, within a namespace.
 using NSSymbolMap = llvm::DenseMap<llvm::StringRef, unsigned>;
 
+struct SymbolMapping {
+  const char *QName;
+  unsigned NSLen;
+  const char *HeaderName;
+};
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dzbarsky wrote:

@aengelke I've reworked the PR to use `EnumStringDef`, it increased the final binary size by around 10KB but saved a bit of source code; I think I'm fine with that given we've successfully captured the relocation removals. WDYT of this approach?

https://github.com/llvm/llvm-project/pull/202663