https://bugs.webkit.org/show_bug.cgi?id=124017

Reviewed by Ryosuke Niwa.

Source/JavaScriptCore:

MapData iterator did not consider the case of the first entries
being holes.  To fix this I've refactored iteration so that we
can perform an initialisation increment on construction, whle
retaining the useful assertion in MapData::const_iterator::operator++

* runtime/MapData.h:
(JSC::MapData::const_iterator::operator++):
(JSC::MapData::const_iterator::internalIncrement):
(JSC::MapData::const_iterator::const_iterator):

LayoutTests:

Test case

* js/map-iterate-first-entry-is-a-hole-expected.txt: Added.
* js/map-iterate-first-entry-is-a-hole.html: Added.
* js/script-tests/map-iterate-first-entry-is-a-hole.js: Added.
(set map0):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@158929 268f45cc-cd09-0410-ab3c-d52691b4dbfc