Merge from the trunk, some Drd-related changes:

Merge from the trunk, some Drd-related changes:

9087 Suppress any error whose top frame is in libc.so. While not very
     elegant, this is an effective way to suppress data race reports
     triggered by glibc's stdio functions (which uses inlined locking
     functions).

9090 Do not only recognize .plt and .plt.got sections inside the
     mapped address range, but also outside the mapped address range
     (necessary for ppc).

9091 Generalized suppression patterns.

9092 Removed mandatory redirections for DRD since these made DRD
     impossible to use on openSUSE 10.3 ppc.

git-svn-id: svn://svn.valgrind.org/valgrind/branches/VALGRIND_3_4_BRANCH@9093