Reviewed by Eric.

    Reviewed by Eric.

        - http://bugs.webkit.org/show_bug.cgi?id=16471
          Completions need to be smaller (or not exist at all)

        SuSpider shows 2.4% speedup.

        Stop using completions in the execution engine.
        Instead, the completion type and label target are both
        stored in the ExecState.

        * API/JSContextRef.cpp: Removed unneeded include of "completion.h".
        * bindings/runtime_method.cpp: Removed unused execute function.
        * bindings/runtime_method.h: Ditto.

        * kjs/ExecState.h: Added completionType, breakOrContinueTarget,
        setCompletionType, setNormalCompletion, setBreakCompletion,
        setContinueCompletion, setReturnValueCompletion, setThrowCompletion,
        setInterruptedCompletion, m_completionType, and m_breakOrContinueTarget.

        * kjs/completion.h: Removed constructor and getter for target
        for break and continue from Completion. This class is now only
        used for the public API to Interpreter and such.

        * kjs/date_object.h: Removed unused execute function.

        * kjs/function.cpp:
        (KJS::FunctionImp::callAsFunction): Removed some unneeded
        exception processing. Updated to call the new execute function
        and to get the completion type from the ExecState. Merged in
        the execute function, which repeated some of the same logic and
        was called only from here.
        (KJS::GlobalFuncImp::callAsFunction): More of the same for eval.
        * kjs/function.h: Removed execute.

        * kjs/interpreter.cpp:
        (KJS::Interpreter::evaluate): Added code to convert the result of
        execut into a Completion.

        * kjs/nodes.cpp:
        (KJS::Node::setErrorCompletion): Renamed from createErrorCompletion.
        Now sets the completion type in the ExecState.
        (KJS::Node::rethrowException): Now sets the completion type in the
        ExecState.
        (KJS::StatementNode::hitStatement): Now sets the completion type in
        the ExecState.
        (KJS::VarStatementNode::execute): Updated to put completion type in
        the ExecState instead of a Completion object.
        (KJS::statementListExecute): Ditto. Also changed the for loop to use
        indices instead of iterators.
        (KJS::BlockNode::execute): Updated return type.
        (KJS::EmptyStatementNode::execute): Updated to put completion type in
        the ExecState instead of a Completion object.
        (KJS::ExprStatementNode::execute): Ditto.
        (KJS::IfNode::execute): Ditto.
        (KJS::DoWhileNode::execute): Ditto. Also streamlined the logic a little
        to make the normal case a little faster and moved the end outside the
        loop so that "break" can do a break.
        (KJS::WhileNode::execute): Ditto.
        (KJS::ForNode::execute): Ditto.
        (KJS::ForInNode::execute): Ditto.
        (KJS::ContinueNode::execute): Updated to put completion type in
        the ExecState instead of a Completion object.
        (KJS::BreakNode::execute): Ditto.
        (KJS::ReturnNode::execute): Ditto.
        (KJS::WithNode::execute): Ditto.
        (KJS::CaseClauseNode::executeStatements): Ditto. Also renamed to have
        execute in its name to reflect the fact that it's a member of the same
        family of functions.
        (KJS::CaseBlockNode::executeBlock): Ditto.
        (KJS::SwitchNode::execute): Ditto.
        (KJS::LabelNode::execute): Ditto.
        (KJS::ThrowNode::execute): Ditto.
        (KJS::TryNode::execute): Ditto.
        (KJS::ProgramNode::execute): Ditto.
        (KJS::EvalNode::execute): Ditto.
        (KJS::FunctionBodyNode::execute): Ditto.
        (KJS::FuncDeclNode::execute): Ditto.

        * kjs/nodes.h: Renamed setErrorCompletion to createErrorCompletion, made
        hitStatement protected, changed return value of execute to a JSValue,
        renamed evalStatements to executeStatements, and evalBlock to executeBlock.

        * kjs/number_object.h: Removed unused execute function.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@28887 268f45cc-cd09-0410-ab3c-d52691b4dbfc