I would like to upstream the attached patch which allows ASTConsumer to select
which function to skip while parsing.
I have been using it to do a online code browser: http://code.woboq.org
Most of the time of my tool is spent in parsing.
And I have to parse the same includes again and again, and some includes have
a lot of inline functions.
By skipping body in already seen includes, I was able to reduce the parsing
time by 30%.
This might also be useful for other tools like refactoring or so.