Changed other instances of malloc.h to stdlib.h for OSX compat

src/datastructures.c

@@ -2,7 +2,7 @@
 #include "hammer.h"
 #include "allocator.h"
 #include <assert.h>
-#include <malloc.h>
+#include <stdlib.h>
 #include <string.h>
 // {{{ counted arrays
 

src/internal.h

@@ -223,7 +223,7 @@ void  h_hashtable_del(HHashTable* ht, void* key);
 void  h_hashtable_free(HHashTable* ht);
 
 #if 0
-#include <malloc.h>
+#include <stdlib.h>
 #define h_arena_malloc(a, s) malloc(s)
 #endif
 

src/pprint.c

@@ -20,7 +20,7 @@
 #include <string.h>
 #include "hammer.h"
 #include "internal.h"
-#include <malloc.h>
+#include <stdlib.h>
 
 typedef struct pp_state {
   int delta;

src/system_allocator.c

-#include <malloc.h>
+#include <stdlib.h>
 #include "internal.h"
 
 static void* system_alloc(HAllocator *allocator, size_t size) {