Merge r14498 from trunk (mention MIPS32/Android as supported platform)


git-svn-id: svn://svn.valgrind.org/valgrind/branches/VALGRIND_3_10_BRANCH@14501 a5019735-40e9-0310-863c-91ae7b9d1cf9
Merge r14499 from trunk (also do unshare and pivot_root on s390x)


git-svn-id: svn://svn.valgrind.org/valgrind/branches/VALGRIND_3_10_BRANCH@14502 a5019735-40e9-0310-863c-91ae7b9d1cf9