Fix vector memory statistics.
2018-11-05 Martin Liska <mliska@suse.cz>
* mem-stats.h (mem_alloc_description::release_instance_overhead):
Return T *.
* vec.c (struct vec_usage): Register m_element_size.
(vec_prefix::register_overhead): New arguments: elements and
element_size.
(vec_prefix::release_overhead): Subtract elements.
* vec.h (struct vec_prefix): Change signature.
(va_heap::reserve): Pass proper arguments.
(va_heap::release): Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@265799 138bc75d-0d04-0410-961f-82ee72b054a4