Support for native in leg, and start moving native tests to a specific test suite.

frog/leg/ssa/builder.dart

Index: frog/leg/ssa/builder.dart
===================================================================
--- frog/leg/ssa/builder.dart	(revision 4390)
+++ frog/leg/ssa/builder.dart	(working copy)
@@ -482,7 +482,7 @@
     if (scopeData == null) return;
     if (scopeData.hasBoxedLoopVariables()) {
       updateCaptureBox(scopeData.boxElement, scopeData.boxedLoopVariables);
-    }    
+    }
   }
 
   void endLoop(HBasicBlock loopEntry) {
@@ -1566,6 +1566,9 @@
         push(new HForeign(
             new SourceString('\$0.$name'), const SourceString('bool'), inputs));
         break;
+      case "native":
+        native.handleSsaNative(this, node);
+        break;
       default:
         throw "Unknown foreign: ${node.selector}";
     }