When calling `MEM_guarded_mallocN_aligned` with an alignment of 4, a pointer that was returned that is 4 byte but not 8 byte aligned. When freeing this pointer, `MEM_guarded_freeN` thinks that it is an illegal pointer, because it asserts that `((intptr_t)memh) & 0x7 == 0`. The fix is to always use at least 8 byte alignment. Reviewers: brecht Differential Revision: https://developer.blender.org/D5529