Make StringSaver::save less ambiguous.

Previously, an expression such as Saver.save(std::string("foo") + "bar")
didn't compile because there is an ambiguity as to whether the argument
is of const Twine& or StringRef.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301512 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed