[PATCH, v8] Vectorized _cpp_clean_line

[Andi Kleen]

> Are they expected?

On a normal optimized C build the preprocessor times are not big enough for 
the fast clean line to really help. Also there is still _cpp_lex_direct which 
is somewhat costly. It's mostly a win for -O0 and for some programs with very
large source code to generated code ratios -- e.g. heavy C++ templates
or windows.h For those it's a nice but not dramatic win.

BTW I suspect the rest of the preprocessor could be still made faster
with some care. Clearly the clang preprocessor still beats it.

-Andi