PRE(mach_msg) on OSX 10.10 64-bit: replace failing assertion
   vg_assert(! (mh->msgh_bits & MACH_SEND_TRAILER));
with a warning message, but let it continue.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14711 a5019735-40e9-0310-863c-91ae7b9d1cf9
Interceot _platform_strncmp also on OSX 10.10.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14712 a5019735-40e9-0310-863c-91ae7b9d1cf9