* vec.h (VEC_stack_alloc): Define different version if
	GATHER_STATISTICS is defined, to accept and ignore MEM_STAT.
	(DEF_VEC_ALLOC_FUNC_P_STACK): Remove MEM_STAT_DECL.
	(DEF_VEC_ALLOC_FUNC_O_STACK): Likewise.
	(DEF_VEC_ALLOC_FUNC_I_STACK): Likewise.

From-SVN: r148562