Do not generate at use site loop phis. It requires live analysis that we currently don't implement.

frog/tests/leg/src/TypeInferenceTest.dart

Index: frog/tests/leg/src/TypeInferenceTest.dart
===================================================================
--- frog/tests/leg/src/TypeInferenceTest.dart	(revision 2800)
+++ frog/tests/leg/src/TypeInferenceTest.dart	(working copy)
@@ -12,12 +12,14 @@
 }
 """;
 
+String anyIdentifier = "[a-zA-Z][a-zA-Z0-9]*";
+
 main() {
   String generated = compile(TEST_ONE, 'sum');
-  RegExp regexp = const RegExp("i = \\(i \\+ 1\\)");
+  RegExp regexp = new RegExp("i = \\($anyIdentifier \\+ 1\\)");
   Expect.isTrue(regexp.hasMatch(generated));
 
-  regexp = const RegExp("sum = \\(sum \\+ i\\)");
+  regexp = new RegExp("sum = \\($anyIdentifier \\+ $anyIdentifier\\)");
   Expect.isTrue(regexp.hasMatch(generated));
 
   regexp = const RegExp('guard\\\$num\\(param0\\)');