[gjs] js: Remove deprecated JS_IsConstructing()

[Philip Chimento <pchimento src gnome org>]

commit 03c0a78b36904762a8245351c06be586f5509d8f
Author: Philip Chimento <philip chimento gmail com>
Date:   Sat Sep 17 20:08:37 2016 -0700

    js: Remove deprecated JS_IsConstructing()
    
    In mozjs31 this is replaced with JS::CallArgs::isConstructing().
    
    https://bugzilla.gnome.org/show_bug.cgi?id=751252

 gjs/jsapi-util.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gjs/jsapi-util.h b/gjs/jsapi-util.h
index 794077f..262e8c2 100644
--- a/gjs/jsapi-util.h
+++ b/gjs/jsapi-util.h
@@ -262,7 +262,7 @@ gjs_##name##_constructor(JSContext  *context,           \
  */
 #define GJS_NATIVE_CONSTRUCTOR_PRELUDE(name)                                   \
     {                                                                          \
-        if (!JS_IsConstructing(context, vp)) {                                 \
+        if (!argv.isConstructing()) {                                          \
             gjs_throw_constructor_error(context);                              \
             return false;                                                      \
         }                                                                      \