Bug 338703 helgrind on arm-linux gets false positives in dynamic loader.

There are a couple of issues with helgrind on arm-linux with glibc:

- Thread creation stack traces cannot unwind through clone
  (cfi ends right after syscall)
- ld.so has a special "hard float" name that isn't recognized as special
  (ld-linux-armhf.so.3)
- Races are found when manipulating GOT sections.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14407 a5019735-40e9-0310-863c-91ae7b9d1cf9
Fix a comment. No functional change.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14408 a5019735-40e9-0310-863c-91ae7b9d1cf9