Fix xallocx(..., MALLOCX_ZERO) bugs.

Zero all trailing bytes of large allocations when
--enable-cache-oblivious configure option is enabled.  This regression
was introduced by 8a03cf039cd06f9fa6972711195055d865673966 (Implement
cache index randomization for large allocations.).

Zero trailing bytes of huge allocations when resizing from/to a size
class that is not a multiple of the chunk size.
4 files changed