If preprocessing results in a token with leading whitespace that was expanded
from a macro in column 0, ensure that we print whitespace before it in the -E
output. Patch by Harald van Dijk!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@202070 91177308-0d34-0410-b5e6-96231b3b80d8