Revert clang::Decl::ClearLinkageCache() patch; implement here instead.
Revert clang::Decl::ClearLinkageCache() patch; implement here instead.

karies/cling,karies/cling,karies/cling,perovic/cling,root-mirror/cling,perovic/cling,karies/cling,marsupial/cling,perovic/cling,marsupial/cling,karies/cling,root-mirror/cling,marsupial/cling,marsupial/cling,root-mirror/cling,root-mirror/cling,root-mirror/cling,marsupial/cling,marsupial/cling,karies/cling,perovic/cling,root-mirror/cling,perovic/cling