[clang] [clang] Add frontend flag to enable support for broken external resugarers (PR #103219)

[Dmitri Gribenko via cfe-commits]

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@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -fsyntax-only -fretain-subst-template-type-parm-type-ast-nodes -ast-dump -ast-dump-filter=dump %s | FileCheck -strict-whitespace %s
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gribozavr wrote:

Could you rename this file to match the flag name?

https://github.com/llvm/llvm-project/pull/103219