avoid string thrashing when formatting names in output.  This
speeds up release-asserts llvm-dis on kc++ from 1.86s to 1.04s (~79%)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54868 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed