Use sys::fs::createTemporaryFile.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185719 91177308-0d34-0410-b5e6-96231b3b80d8
[TRE] Merged several tests into the the test basic.ll.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185723 91177308-0d34-0410-b5e6-96231b3b80d8