functions.

ut_malloc_low(): Flag the block with UNIV_MEM_ALLOC().  Do not flag the
block with UNIV_MEM_FREE() in ut_free(), because it would cause bogus
Valgrind warnings in the underlying memory allocator.

mem_pool_create(): Flag the data area with UNIV_MEM_FREE().

mem_pool_fill_free_list(): Flag the area header with UNIV_MEM_ALLOC().

mem_area_alloc(): Flag the data area with UNIV_MEM_ALLOC().

mem_area_free(): Flag the data area with UNIV_MEM_FREE().

mem_heap_alloc(): Flag the buffer with UNIV_MEM_ALLOC().

mem_heap_block_free(): Flag the block with UNIV_MEM_FREE().

mem_heap_free_top(): Flag the block with UNIV_MEM_FREE().