[clang] [clang] Don't use `VarDecl` of local variables as `ManglingContextDecl` for lambdas (PR #179035)

[Jan Kokemüller via cfe-commits]

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@@ -322,7 +308,8 @@ Sema::getCurrentMangleNumberContext(const DeclContext *DC) {
         if (LexicalDC->isRecord())
           return DefaultArgument;
     } else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
-      if (Var->getMostRecentDecl()->isInline())
+      if (Var->getMostRecentDecl()->isInline() ||
+          IsExternallyVisibleInModulePurview(Var))
         return InlineVariable;
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jiixyj wrote:

OK, for readability I have split this out into a new context kind `ExternallyVisibleVariableInModulePurview` that is treated the same as `InlineVariable` and `TemplatedVariable` below.

https://github.com/llvm/llvm-project/pull/179035