Reviewed by Oliver.
        
        - initialize local vars as side effect of call instead of in bytecode
        1.004x speedup on SunSpider.

        This removes just the dispatch overhead for these loads - in the
        future, dead store elimination might be able to eliminate them
        entirely.
        
        * VM/CodeGenerator.cpp:
        (KJS::CodeGenerator::CodeGenerator): For function blocks, don't
        emit loads of undefined for var initialization.
        * VM/Machine.cpp:
        (KJS::slideRegisterWindowForCall): Instead, initialize locals
        as part of the call.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@34541 268f45cc-cd09-0410-ab3c-d52691b4dbfc