[clang] [clang-tools-extra] [Clang][AST] Introduce `ExplicitInstantiationDecl` to preserve source info and fix diagnostic locations (PR #191658)

[Matheus Izvekov via cfe-commits]

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@@ -2936,6 +2936,20 @@ void TextNodeDumper::VisitAccessSpecDecl(const AccessSpecDecl *D) {
   dumpAccessSpecifier(D->getAccess());
 }
 
+void TextNodeDumper::VisitExplicitInstantiationDecl(
+    const ExplicitInstantiationDecl *D) {
+  dumpTemplateSpecializationKind(D->getTemplateSpecializationKind());
+  if (D->isExternTemplate())
+    OS << " extern";
+  OS << " template";
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mizvekov wrote:

You don't need to put this here if it's not a flag conditional to anything.

https://github.com/llvm/llvm-project/pull/191658