https://bugs.webkit.org/show_bug.cgi?id=79446

Reviewed by Sam Weinig.

lastIndex should be a regular data descriptor, with the attributes configurable:false,
enumerable:false, writable:true. As such, it should be possible to reconfigure writable
as false. If the lastIndex property is reconfigured to be read-only, we should respect
this correctly.

Source/JavaScriptCore: 

* runtime/CommonIdentifiers.h:
    - Removed some unused identifiers, added lastIndex.
* runtime/RegExpObject.cpp:
(JSC::RegExpObject::getOwnPropertySlot):
    - lastIndex is no longer a static value, provided specific handling.
(JSC::RegExpObject::getOwnPropertyDescriptor):
    - lastIndex is no longer a static value, provided specific handling.
(JSC::RegExpObject::deleteProperty):
    - lastIndex is no longer a static value, provided specific handling.
(JSC::RegExpObject::getOwnPropertyNames):
    - lastIndex is no longer a static value, provided specific handling.
(JSC::RegExpObject::getPropertyNames):
    - lastIndex is no longer a static value, provided specific handling.
(JSC::reject):
    - helper function for defineOwnProperty.
(JSC::RegExpObject::defineOwnProperty):
    - lastIndex is no longer a static value, provided specific handling.
(JSC::RegExpObject::put):
    - lastIndex is no longer a static value, provided specific handling.
(JSC::RegExpObject::match):
    - Pass setLastIndex an ExecState, so it can throw if read-only.
* runtime/RegExpObject.h:
(JSC::RegExpObject::setLastIndex):
    - Pass setLastIndex an ExecState, so it can throw if read-only.
(RegExpObjectData):
    - Added lastIndexIsWritable.
* runtime/RegExpPrototype.cpp:
(JSC::regExpProtoFuncCompile):
    - Pass setLastIndex an ExecState, so it can throw if read-only.

LayoutTests: 

* fast/regex/lastIndex-expected.txt: Added.
* fast/regex/lastIndex.html: Added.
* fast/regex/script-tests/lastIndex.js: Added.
    - Added test cases for correct handling of lastIndex.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@109008 268f45cc-cd09-0410-ab3c-d52691b4dbfc