SmallVector: Move emplace_back to SmallVectorImpl.

This resolves the strange effect that emplace_back is only available
when the type contained in the vector is not trivially copyable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228496 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed