Forward malloc_iterate/disable/enable to dispatch.

Same as perfetto, not sure why this doesn't forward to the previous
dispatch table.

Fixed extended test that had reversed the malloc_enable/malloc_disable call.

Bug: N/A
Test: atest malloc_hooks_system_tests
Change-Id: I2c9878c99ef5d7952c1148ebdd40d7cd309551ad
diff --git a/libc/malloc_hooks/malloc_hooks.cpp b/libc/malloc_hooks/malloc_hooks.cpp
index 1ba8696..54f24dd 100644
--- a/libc/malloc_hooks/malloc_hooks.cpp
+++ b/libc/malloc_hooks/malloc_hooks.cpp
@@ -209,14 +209,17 @@
   return g_dispatch->posix_memalign(memptr, alignment, size);
 }
 
-int hooks_malloc_iterate(uintptr_t, size_t, void (*)(uintptr_t, size_t, void*), void*) {
-  return 0;
+int hooks_malloc_iterate(uintptr_t base, size_t size,
+                         void (*callback)(uintptr_t base, size_t size, void* arg), void* arg) {
+  return g_dispatch->malloc_iterate(base, size, callback, arg);
 }
 
 void hooks_malloc_disable() {
+  g_dispatch->malloc_disable();
 }
 
 void hooks_malloc_enable() {
+  g_dispatch->malloc_enable();
 }
 
 ssize_t hooks_malloc_backtrace(void*, uintptr_t*, size_t) {