Added PTH optimization to not process entire blocks of tokens that appear in skipped preprocessor blocks.  This improves PTH speed by 6%.  The code for this optimization itself is not very optimized, and will get cleaned up.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60956 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed