This patch will be merged with its predecessor before being committed, it is
kept separate for now to ease reviewing.
---
 malloc/arena.c              |   8 +++
 malloc/malloc.c             | 112 +++++++++++++++++++++++++++++-------
 sysdeps/generic/libc-mtag.h |   2 +-
 3 files changed, 101 insertions(+), 21 deletions(-)