Test for virtual instead of pure here. It has the exact same effect, and John
claims it will improve performance.


git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@174341 91177308-0d34-0410-b5e6-96231b3b80d8
Remove dead code related to the now defunct PCH stat cache.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@174342 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "Remove sparse text on diagnostic options.  These are not really documented anywhere, and they really aren't for normal users."

I changed my mind.  We should just document these in the man page.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@174344 91177308-0d34-0410-b5e6-96231b3b80d8