system/kernel: add missing posix_memalign, fixes guarded_heap

Change-Id: Id035aa607a5a2a8545a85416d97cdd4a1b069203
Reviewed-on: https://review.haiku-os.org/c/haiku/+/8369
Reviewed-by: waddlesplash <[email protected]>

src/system/kernel/guarded_heap.cpp

@@ -944,6 +944,17 @@ memalign_etc(size_t alignment, size_t size, uint32 flags)
 }
 
 
+extern "C" int
+posix_memalign(void** _pointer, size_t alignment, size_t size)
+{
+	if ((alignment & (sizeof(void*) - 1)) != 0 || _pointer == NULL)
+		return B_BAD_VALUE;
+
+	*_pointer = guarded_heap_allocate(sGuardedHeap, size, alignment, 0);
+	return 0;
+}
+
+
 void
 free_etc(void *address, uint32 flags)
 {