move __memalign declaration to malloc_impl.h

the malloc-implementation-private header is the only right place for
this, because, being in the reserved namespace, __memalign is not
interposable and thus not valid to use anywhere else. anything outside
of the malloc implementation must call an appropriate-namespace public
function (aligned_alloc or posix_memalign).

1 files changed, 2 insertions, 0 deletions

diff --git a/src/internal/malloc_impl.h b/src/internal/malloc_impl.h
index 40d16960..88b4f670 100644
--- a/src/internal/malloc_impl.h
+++ b/src/internal/malloc_impl.h
@@ -12,6 +12,8 @@ void *__expand_heap(size_t *);
 
 void __malloc_donate(char *, char *);
 
+void *__memalign(size_t, size_t);
+
 struct chunk {
 	size_t psize, csize;
 	struct chunk *next, *prev;