When sys_heap_realloc() is expressed in terms of sys_heap_aligned_realloc()
it invokes a longer aligned allocation code path with an extra runtime
overhead even though no alignment is necessary.
Let's reference and invoke the aligned allocation code path only when an
actual aligned allocation is requested. This opens the possibility for
the linker to garbage-collect the aligning code otherwise.
Improve realloc documentation while at it.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
11021cdd4f