FunctionObject: Mark name/length property configurable

In ES5, these were not configurable, but ES6 changed the behavior.

For length, refer to:
    9.2.4 (FunctionInitialize)
    17 (ECMAScript Standard Built-in Objects):
        Unless otherwise specified, the length property of a built-in Function
        object has the attributes { [[Writable]]: false, [[Enumerable]]: false,
        [[Configurable]]: true }.
    19.2.2.1 Function.length
    19.2.3.2 (Function.prototype.bind)
    19.2.4.1 (Function instances, length)

For name, refer to:
    9.2.11 (SetFunctionName)

This does regress test262 for ES5 for me a little, but improves our es6 test
coverage a bit (~682 more tests pass, +1.5%).

Change-Id: Icda7c9068dc3e6e4e4aebbb0d359868a30343013
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/qml/jsruntime/qv4global_p.h b/src/qml/jsruntime/qv4global_p.h
index 66861bf697..b0d14fc2b4 100644
--- a/src/qml/jsruntime/qv4global_p.h
+++ b/src/qml/jsruntime/qv4global_p.h
@@ -258,6 +258,7 @@ enum PropertyFlag {
     Attr_NotEnumerable = 0x4,
     Attr_NotConfigurable = 0x8,
     Attr_ReadOnly = Attr_NotWritable|Attr_NotEnumerable|Attr_NotConfigurable,
+    Attr_ReadOnly_ButConfigurable = Attr_NotWritable|Attr_NotEnumerable,
     Attr_Invalid = 0xff
 };