* malloc/malloc.c (DEFAULT_MMAP_THRESHOLD_MAX): For 32-bit

* malloc/malloc.c (DEFAULT_MMAP_THRESHOLD_MAX): For 32-bit

	platforms define as 1MB.  For 64-bit platforms as 32MB.  The lower
	limit is needed to avoid the exploding of the address space
	requirement for secondary heaps.
	* malloc/arena.c (HEAP_MAX_SIZE): Define using
	DEFAULT_MMAP_THRESHOLD_MAX if it is defined.