[clang] clang_EvalResult_getAsCXString impl (PR #134551)

[Aaron Ballman via cfe-commits]

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@@ -44,6 +45,11 @@ typedef struct {
   unsigned Count;
 } CXStringSet;
 
+typedef struct {
+  const char *string;
+  size_t length;
+} CStringInfo;
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AaronBallman wrote:

Because we can now feel a bit more free to add a different `private_flags` value, I think we're fine to not leave space for future expansion. WDYT?

https://github.com/llvm/llvm-project/pull/134551