Fix multiple debugger issues. (#1640)

- Wait for free byte code pointers during garbage collection.
- Detect incorrect free requests in the debugger server.
- Ignore byte code blocks loaded from snapshot.
- Use memmove instead of memcpy to avoid receive buffer corruption.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/ecma/base/ecma-gc.c

@@ -708,10 +708,18 @@ ecma_gc_run (jmem_free_unused_memory_severity_t severity) /**< gc severity */
 void
 ecma_free_unused_memory (jmem_free_unused_memory_severity_t severity) /**< severity of the request */
 {
+#ifdef JERRY_DEBUGGER
+  while ((JERRY_CONTEXT (debugger_flags) & JERRY_DEBUGGER_CONNECTED)
+         && JERRY_CONTEXT (debugger_byte_code_free_tail) != ECMA_NULL_POINTER)
+  {
+    /* Wait until all byte code is freed or the connection is aborted. */
+    jerry_debugger_receive ();
+  }
+#endif /* JERRY_DEBUGGER */
+
   if (severity == JMEM_FREE_UNUSED_MEMORY_SEVERITY_LOW)
   {
-
- #ifndef CONFIG_ECMA_PROPERTY_HASHMAP_DISABLE
+#ifndef CONFIG_ECMA_PROPERTY_HASHMAP_DISABLE
     if (JERRY_CONTEXT (ecma_prop_hashmap_alloc_state) > ECMA_PROP_HASHMAP_ALLOC_ON)
     {
       --JERRY_CONTEXT (ecma_prop_hashmap_alloc_state);