Merge instance into context (#2501)

There was quite some confusion about terminology around instances
and contexts. All the docs mentioned external contexts but
functions and types were referring to instances, and the relation
between these two concepts were not clear. This commit keeps
(external) context as the only surviving concept.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

jerry-main/main-unix.c

@@ -401,15 +401,15 @@ check_usage (bool condition, /**< the condition that must hold */
 #ifdef JERRY_ENABLE_EXTERNAL_CONTEXT
 
 /**
- * The alloc function passed to jerry_create_instance
+ * The alloc function passed to jerry_create_context
  */
 static void *
-instance_alloc (size_t size,
-                void *cb_data_p)
+context_alloc (size_t size,
+               void *cb_data_p)
 {
   (void) cb_data_p; /* unused */
   return malloc (size);
-} /* instance_alloc */
+} /* context_alloc */
 
 #endif /* JERRY_ENABLE_EXTERNAL_CONTEXT */
 
@@ -607,8 +607,8 @@ main (int argc,
 
 #ifdef JERRY_ENABLE_EXTERNAL_CONTEXT
 
-  jerry_instance_t *instance_p = jerry_create_instance (512*1024, instance_alloc, NULL);
-  jerry_port_default_set_instance (instance_p);
+  jerry_context_t *context_p = jerry_create_context (512*1024, context_alloc, NULL);
+  jerry_port_default_set_context (context_p);
 
 #endif /* JERRY_ENABLE_EXTERNAL_CONTEXT */
 
@@ -873,7 +873,7 @@ main (int argc,
 
   jerry_cleanup ();
 #ifdef JERRY_ENABLE_EXTERNAL_CONTEXT
-  free (instance_p);
+  free (context_p);
 #endif /* JERRY_ENABLE_EXTERNAL_CONTEXT */
   return ret_code;
 } /* main */