Refactored BinaryExpr.
Refactored BinaryExpr.

flimzy/gopherjs,ebroder/gopherjs,rasata/gopherjs,bpowers/gopherjs,Yanjing123/gopherjs,nmfzone/gopherjs,jeremyschlatter/gopherjs,Archs/gopherjs,gopherjs/gopherjs,jeremyschlatter/gopherjs,albrow/gopherjs,albrow/gopherjs,roth1002/gopherjs,rasata/gopherjs,Yanjing123/gopherjs,nmfzone/gopherjs,gopherjs/gopherjs,bpowers/gopherjs,roth1002/gopherjs,jargv/gopherjs,govlas/gopherjs,roth1002/gopherjs,bpowers/gopherjs,nmfzone/gopherjs,Archs/gopherjs,flimzy/gopherjs,gopherjs/gopherjs,jargv/gopherjs,ebroder/gopherjs,jeremyschlatter/gopherjs,Yanjing123/gopherjs,jargv/gopherjs,gopherjs/gopherjs,govlas/gopherjs,govlas/gopherjs,albrow/gopherjs,Archs/gopherjs,gopherjs/gopherjs,rasata/gopherjs,ebroder/gopherjs,flimzy/gopherjs