[clang] [Clang] fix assertion failure in ::template operator parsing (PR #194097)

[via cfe-commits]

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@@ -472,6 +472,7 @@ Improvements to Coverage Mapping
 Bug Fixes in This Version
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+- Fixed a preprocessor assertion failure triggered when parsing an invalid template-id starting with `::template operator`. (#GH186582)
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Serosh-commits wrote:

> There is a c++ section

moving it thanks

https://github.com/llvm/llvm-project/pull/194097