Fix ADD_CALL_CHAIN() placement to follow GC_store_debug_info_inner call

Issue #613 (bdwgc).

This might be important for the case of malloc redirection as
backtrace() need to be called without the allocator lock held.

* dbg_mlc.c (store_debug_info, GC_debug_generic_malloc_inner): Call
ADD_CALL_CHAIN() right after GC_store_debug_info_inner() call (instead
of before it).
* gcj_mlc.c (GC_debug_gcj_malloc): Likewise.
* dbg_mlc.c (GC_debug_generic_malloc_inner): Declare result local
variable.

dbg_mlc.c

@@ -295,8 +295,8 @@ static void *store_debug_info(void *base, size_t lb,
     LOCK();
     if (!GC_debugging_started)
         GC_start_debugging_inner();
-    ADD_CALL_CHAIN(base, ra);
     result = GC_store_debug_info_inner(base, (word)lb, s, i);
+    ADD_CALL_CHAIN(base, ra);
     UNLOCK();
     return result;
 }
@@ -570,7 +570,7 @@ STATIC void * GC_debug_generic_malloc(size_t lb, int k, GC_EXTRA_PARAMS)
   GC_INNER void * GC_debug_generic_malloc_inner(size_t lb, int k,
                                                 unsigned flags)
   {
-    void *base;
+    void *base, *result;
 
     GC_ASSERT(I_HOLD_LOCK());
     base = GC_generic_malloc_inner(SIZET_SAT_ADD(lb, DEBUG_BYTES), k, flags);
@@ -581,8 +581,9 @@ STATIC void * GC_debug_generic_malloc(size_t lb, int k, GC_EXTRA_PARAMS)
     }
     if (!GC_debugging_started)
         GC_start_debugging_inner();
+    result = GC_store_debug_info_inner(base, (word)lb, "INTERNAL", 0);
     ADD_CALL_CHAIN(base, GC_RETURN_ADDR);
-    return GC_store_debug_info_inner(base, (word)lb, "INTERNAL", 0);
+    return result;
   }
 #endif /* DBG_HDRS_ALL */
 

gcj_mlc.c

@@ -216,8 +216,8 @@ GC_API GC_ATTR_MALLOC void * GC_CALL GC_debug_gcj_malloc(size_t lb,
     if (!GC_debugging_started) {
         GC_start_debugging_inner();
     }
-    ADD_CALL_CHAIN(base, ra);
     result = GC_store_debug_info_inner(base, (word)lb, s, i);
+    ADD_CALL_CHAIN(base, ra);
     UNLOCK();
     GC_dirty(result);
     REACHABLE_AFTER_DIRTY(ptr_to_struct_containing_descr);