https://bugs.webkit.org/show_bug.cgi?id=92282

Reviewed by Geoffrey Garen.

Replace the existing functions for formating GregorianDateTime
with one single function. This removes some code duplications
in DatePrototype and is a preperation to fix encoding issues,
since we can add UChar* values to the resulting string now.

* runtime/DateConstructor.cpp:
(JSC::callDate):
* runtime/DateConversion.cpp:
(JSC::formatDateTime):
* runtime/DateConversion.h:
(JSC):
* runtime/DatePrototype.cpp:
(JSC::formateDateInstance):
(JSC::dateProtoFuncToString):
(JSC::dateProtoFuncToUTCString):
(JSC::dateProtoFuncToDateString):
(JSC::dateProtoFuncToTimeString):
(JSC::dateProtoFuncToGMTString):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@124817 268f45cc-cd09-0410-ab3c-d52691b4dbfc