Change the backtrace filtering machinery for the helgrind regression 
bucket. Instead of removing what we don't want to see in a backtrace
(e.g. path segments through libc and libpthread), we simply keep what
we do want to see. That way .exp files can be generic.
We need to make sure that GCC inlining does not get in the way. So all
the ..._WRK function in hg_intercepts.c are attributed as noinline.
The backtrace filtering is done in the new filter_helgrind script.
filter_stderr is simplified quite a bit.
Fixes bug #281468. See also the comments #5 and #6 there.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12045 a5019735-40e9-0310-863c-91ae7b9d1cf9
38 files changed