Revert "cps-ir: Support foreign code."

pkg/compiler/lib/src/tree_ir/optimization/statement_rewriter.dart

Index: pkg/compiler/lib/src/tree_ir/optimization/statement_rewriter.dart
diff --git a/pkg/compiler/lib/src/tree_ir/optimization/statement_rewriter.dart b/pkg/compiler/lib/src/tree_ir/optimization/statement_rewriter.dart
index 500c9636089cb308ec4ccbe78feb171a30518d03..b44ca6dfb819005b7d894da1825c9bae9cbd7607 100644
--- a/pkg/compiler/lib/src/tree_ir/optimization/statement_rewriter.dart
+++ b/pkg/compiler/lib/src/tree_ir/optimization/statement_rewriter.dart
@@ -952,18 +952,6 @@ class StatementRewriter extends Transformer implements Pass {
   Statement getBranch(If node, bool polarity) {
     return polarity ? node.thenStatement : node.elseStatement;
   }
-
-  @override
-  Expression visitForeignExpression(ForeignExpression node) {
-    _rewriteList(node.arguments);
-    return node;
-  }
-
-  @override
-  Statement visitForeignStatement(ForeignStatement node) {
-    _rewriteList(node.arguments);
-    return node;
-  }
 }
 
 /// Result of combining two expressions, with the potential for reverting the