[9.18] fix: dev: Stop using malloc_usable_size and malloc_size
The malloc_usable_size()
can return size larger than originally allocated and when these sizes disagree the fortifier enabled by _FORTIFY_SOURCE=3
detects overflow and stops the named
execution abruptly. Stop using these convenience functions as they are primary used for introspection-only.
Closes #4880 (closed)
Backport of MR !9400 (merged)