Separating all of the simple binary expression nodes into multiple classes

Separating all of the simple binary expression nodes into multiple classes

Reviewed by Maciej

Separating all of the simple (eg. non-read-modify-write) binary operators into separate classes in preparation for further JS optimisations.

Happily this produces a 0.8% to 1.0% performance increase in SunSpider with no further work.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@26925 268f45cc-cd09-0410-ab3c-d52691b4dbfc