use best-fit instead of first-fit when reusing a MacroArgs object,
this speeds up Eonly on the testcase in PR5888 from 30.5s to 0.85s


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@92203 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed