restructure code a bit: there are two potential issues
worth asserting about in this code: 1) if the source range
is bogus (begin loc after end loc), and 2) if the client
is trying to highlight a range that is purely whitespace.

It is possible to just silently ignore #2, but it seems like
it is always a bug, so lets keep asserting on this condition,
but with a better assert message.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95998 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed