Implement Valgrind support, as well as the redzone and quarantine
features, which help Valgrind detect memory errors. Redzones are only
implemented for small objects because the changes necessary to support
redzones around large and huge objects are complicated by in-place
reallocation, to the point that it isn't clear that the maintenance
burden is worth the incremental improvement to Valgrind support.
Merge arena_salloc() and arena_salloc_demote().
Refactor i[v]salloc() to expose the 'demote' option.
s/PAGE_SHIFT/LG_PAGE/g and s/PAGE_SIZE/PAGE/g.
Remove remnants of the dynamic-page-shift code.
Rename the "arenas.pagesize" mallctl to "arenas.page".
Remove the "arenas.chunksize" mallctl, which is redundant with
"opt.lg_chunk".
It turns out some OSX system libraries (like CoreGraphics on 10.6) like
to call malloc_zone_* functions, but giving them pointers that weren't
allocated with the zone they are using.
Possibly, they do malloc_zone_malloc(malloc_default_zone()) before we
register the jemalloc zone, and malloc_zone_realloc(malloc_default_zone())
after. malloc_default_zone() returning a different value in both cases.
I tested a build from 10.7 run on 10.7 and 10.6, and a build from 10.6
run on 10.6. The AC_COMPILE_IFELSE limbo is to avoid running a program
during configure, which presumably makes it work when cross compiling
for iOS.
Add the --with-mangling configure option, which can be used to specify
name mangling on a per public symbol basis that takes precedence over
--with-jemalloc-prefix.
Expose the memalign() and valloc() overrides even if
--with-jemalloc-prefix is specified. This change does no real harm, and
simplifies the code.
