tree-ir: Always declare captured variables.

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

Index: pkg/compiler/lib/src/tree_ir/tree_ir_builder.dart
diff --git a/pkg/compiler/lib/src/tree_ir/tree_ir_builder.dart b/pkg/compiler/lib/src/tree_ir/tree_ir_builder.dart
index 0683911c095fc46bf697f617d93745040fc4257f..c67b2b58f287aec8466755c4a07e8ed16e0fc5f9 100644
--- a/pkg/compiler/lib/src/tree_ir/tree_ir_builder.dart
+++ b/pkg/compiler/lib/src/tree_ir/tree_ir_builder.dart
@@ -69,9 +69,6 @@ class Builder implements cps_ir.Visitor<Node> {
   cps_ir.Parameter thisParameter;
   cps_ir.Continuation returnContinuation;
 
-  /// Number of loops enclosing the currently visited node.
-  int enclosingLoops = 0;
-
   Builder parent;
 
   Builder(this.internalError, [this.parent]);
@@ -476,7 +473,7 @@ class Builder implements cps_ir.Visitor<Node> {
     Statement body = visit(node.body);
     // If the variable was captured by an inner function in the body, this
     // must be declared here so we assign to a fresh copy of the variable.
-    if (variable.isCaptured && enclosingLoops > 0) {
+    if (variable.isCaptured) {
       return new VariableDeclaration(variable, value, body);
     }
     return Assign.makeStatement(variable, value, body);
@@ -543,7 +540,7 @@ class Builder implements cps_ir.Visitor<Node> {
             if (cont.isRecursive) {
               return node.isRecursive
                   ? new Continue(labels[cont])
-                  : new WhileTrue(labels[cont], makeLoopBody(cont.body));
+                  : new WhileTrue(labels[cont], visit(cont.body));
             } else {
               if (cont.hasExactlyOneUse) {
                 if (safeForInlining.contains(cont)) {
@@ -557,13 +554,6 @@ class Builder implements cps_ir.Visitor<Node> {
     }
   }
 
-  Statement makeLoopBody(cps_ir.Expression body) {
-    ++enclosingLoops;
-    Statement result = visit(body);
-    --enclosingLoops;
-    return result;
-  }
-
   Statement visitBranch(cps_ir.Branch node) {
     Expression condition = visit(node.condition);
     Statement thenStatement, elseStatement;