dart2js cps: Clean up and avoid processing unreachable code.

pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart

Index: pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
diff --git a/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart b/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
index bd4baabdded66a78f6c58b845781d5f5b292032c..80e4f28894e6db0c288a52fa9f7b3e46443a21f4 100644
--- a/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
+++ b/pkg/compiler/lib/src/tree_ir/tree_ir_nodes.dart
@@ -114,7 +114,6 @@ class Variable extends Node {
 
   /// Number of places where this variable occurs as:
   /// - left-hand of an [Assign]
-  /// - left-hand of a [FunctionDeclaration]
   /// - parameter in a [FunctionDefinition]
   /// - catch parameter in a [Try]
   int writeCount = 0;
@@ -437,20 +436,6 @@ class Not extends Expression {
   accept1(ExpressionVisitor1 visitor, arg) => visitor.visitNot(this, arg);
 }
 
-/// Currently unused.
-///
-/// See CreateFunction in the cps_ir_nodes.dart.
-class FunctionExpression extends Expression {
-  final FunctionDefinition definition;
-
-  FunctionExpression(this.definition);
-
-  accept(ExpressionVisitor visitor) => visitor.visitFunctionExpression(this);
-  accept1(ExpressionVisitor1 visitor, arg) {
-    return visitor.visitFunctionExpression(this, arg);
-  }
-}
-
 /// A [LabeledStatement] or [WhileTrue] or [For].
 abstract class JumpTarget extends Statement {
   Label get label;
@@ -988,7 +973,6 @@ abstract class ExpressionVisitor<E> {
   E visitLiteralList(LiteralList node);
   E visitLiteralMap(LiteralMap node);
   E visitTypeOperator(TypeOperator node);
-  E visitFunctionExpression(FunctionExpression node);
   E visitGetField(GetField node);
   E visitSetField(SetField node);
   E visitGetStatic(GetStatic node);
@@ -1026,7 +1010,6 @@ abstract class ExpressionVisitor1<E, A> {
   E visitLiteralList(LiteralList node, A arg);
   E visitLiteralMap(LiteralMap node, A arg);
   E visitTypeOperator(TypeOperator node, A arg);
-  E visitFunctionExpression(FunctionExpression node, A arg);
   E visitGetField(GetField node, A arg);
   E visitSetField(SetField node, A arg);
   E visitGetStatic(GetStatic node, A arg);
@@ -1088,8 +1071,6 @@ abstract class RecursiveVisitor implements StatementVisitor, ExpressionVisitor {
   visitExpression(Expression e) => e.accept(this);
   visitStatement(Statement s) => s.accept(this);
 
-  visitInnerFunction(FunctionDefinition node);
-
   visitVariable(Variable variable) {}
 
   visitVariableUse(VariableUse node) {
@@ -1154,10 +1135,6 @@ abstract class RecursiveVisitor implements StatementVisitor, ExpressionVisitor {
     node.typeArguments.forEach(visitExpression);
   }
 
-  visitFunctionExpression(FunctionExpression node) {
-    visitInnerFunction(node.definition);
-  }
-
   visitLabeledStatement(LabeledStatement node) {
     visitStatement(node.body);
     visitStatement(node.next);
@@ -1309,10 +1286,6 @@ abstract class Transformer implements ExpressionVisitor<Expression>,
 }
 
 class RecursiveTransformer extends Transformer {
-  void visitInnerFunction(FunctionDefinition node) {
-    node.body = visitStatement(node.body);
-  }
-
   void _replaceExpressions(List<Expression> list) {
     for (int i = 0; i < list.length; i++) {
       list[i] = visitExpression(list[i]);
@@ -1389,11 +1362,6 @@ class RecursiveTransformer extends Transformer {
     return node;
   }
 
-  visitFunctionExpression(FunctionExpression node) {
-    visitInnerFunction(node.definition);
-    return node;
-  }
-
   visitLabeledStatement(LabeledStatement node) {
     node.body = visitStatement(node.body);
     node.next = visitStatement(node.next);