Simplify loop that worked around bugs in old GCC/Xcode.

GCC 4.0.1 and Xcode 2 are no longer supported for building llvm/clang.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204705 91177308-0d34-0410-b5e6-96231b3b80d8