Simplified bytecode generation by merging prefix and postfix nodes
https://bugs.webkit.org/show_bug.cgi?id=113925

Reviewed by Filip Pizlo.

PostfixNode now inherits from PrefixNode, so when we detect that we're
in a context where postifx and prefix are equivalent, PostFixNode can
just call through to PrefixNode codegen, instead of duplicating the
logic.

* bytecompiler/NodesCodegen.cpp:
(JSC::PostfixNode::emitResolve):
(JSC::PostfixNode::emitBracket):
(JSC::PostfixNode::emitDot):
* parser/NodeConstructors.h:
(JSC::PostfixNode::PostfixNode):
* parser/Nodes.h:
(JSC):
(PrefixNode):
(PostfixNode):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147658 268f45cc-cd09-0410-ab3c-d52691b4dbfc