Ensure that any TypoExprs in the arguments to bultins with custom type
checking are handled before the custom type checking is performed.

Fixes PR21669.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@222797 91177308-0d34-0410-b5e6-96231b3b80d8
CodeGen: Fix emission of __atomic_compare_exchange

We (wrongly) discarded the return value of the call.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@222798 91177308-0d34-0410-b5e6-96231b3b80d8