[clang] [Clang] Report an error and crash on source location exhaustion in macros (PR #69908)

[Ilya Biryukov via cfe-commits]

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@@ -356,6 +356,8 @@ def err_file_modified : Error<
   "file '%0' modified since it was first processed">, DefaultFatal;
 def err_file_too_large : Error<
   "sorry, unsupported: file '%0' is too large for Clang to process">;
+def err_expansions_too_large : Error<
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ilya-biryukov wrote:

I also don't feel strongly there. The reason I introduced a new warning is because this could theoretically happen without any `#include` and I did not want to touch the existing error message.

https://github.com/llvm/llvm-project/pull/69908