Remove medium size classes, because concurrent dirty page purging is
no longer capable of purging inactive dirty pages inside active runs
(due to recent arena/bin locking changes).
Enhance tcache to support caching large objects, so that the same range
of size classes is still cached, despite the removal of medium size
class support.
Don't look for a shared libunwind if --with-static-libunwind is
specified.
Set SONAME when linking the shared libjemalloc.
Add DESTDIR support.
Add install_{include,lib/man} build targets.
Clean up compiler flag configuration.
Add the --disable-prof-libgcc configure option, and add backtracing
based on libgcc, which is used by default.
Fix a bug in hash().
Fix various configuration-dependent compilation errors.
Add the 'G'/'g' and 'H'/'h' MALLOC_OPTIONS flags.
Add the malloc_tcache_flush() function.
Disable thread-specific caching until the application goes multi-threaded.
jemalloc is configured.
Modify arena_malloc() API to avoid unnecessary choose_arena() calls. Remove
unnecessary code from choose_arena().
Enable lazy-lock by default, now that choose_arena() is both faster and out of
the critical path.
Implement objdir support in the build system.
