Revert "cps-ir: Support foreign code."

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

Index: pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
diff --git a/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart b/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
index 90c0b69577ac486b89976498474657cb73a978eb..fee1dd7adcb33d52b63659533e63a44f2bcabc96 100644
--- a/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
+++ b/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
@@ -172,10 +172,6 @@ class BlockCollector extends StatementVisitor {
     _addStatement(node);
     visitStatement(node.next);
   }
-
-  visitForeignStatement(ForeignStatement node) {
-    _addStatement(node);
-  }
 }
 
 class TreeTracer extends TracerUtil with StatementVisitor {
@@ -325,11 +321,6 @@ class TreeTracer extends TracerUtil with StatementVisitor {
   String expr(Expression e) {
     return e.accept(new SubexpressionVisitor(names));
   }
-
-  @override
-  visitForeignStatement(ForeignStatement node) {
-    printStatement(null, 'foreign');
-  }
 }
 
 class SubexpressionVisitor extends ExpressionVisitor<String> {
@@ -520,12 +511,6 @@ class SubexpressionVisitor extends ExpressionVisitor<String> {
   }
 
   @override
-  String visitForeignExpression(ForeignExpression node) {
-    String arguments = node.arguments.map(visitExpression).join(', ');
-    return 'Foreign "${node.codeTemplate}"($arguments)';
-  }
-
-  @override
   String visitApplyBuiltinOperator(ApplyBuiltinOperator node) {
     String args = node.arguments.map(visitExpression).join(', ');
     return 'ApplyBuiltinOperator ${node.operator} ($args)';