Use llvm:Twine instead of std::to_string.

std::to_string is not available from the Android NDK.

Reviewers: lhames, ovyalov, chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19638

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267829 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed