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git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@216777 91177308-0d34-0410-b5e6-96231b3b80d8
Fix for PR20660, where unexpanded parameter pack in function parameter clause causes clang to crash.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@216778 91177308-0d34-0410-b5e6-96231b3b80d8
Make all virtual member pointers use variadic musttail calls

This avoids encoding information about the function prototype into the
thunk at the cost of some function prototype bitcast gymnastics.

Fixes PR20653.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@216782 91177308-0d34-0410-b5e6-96231b3b80d8