dart2js: Use frequency of occurence to sort metadata indices.

pkg/compiler/lib/src/ssa/types_propagation.dart

Index: pkg/compiler/lib/src/ssa/types_propagation.dart
diff --git a/pkg/compiler/lib/src/ssa/types_propagation.dart b/pkg/compiler/lib/src/ssa/types_propagation.dart
index 71abe6c3ed5bfa4df8dbb65ad9df38538f69b6fe..679b015b88b7971b21ac047399b38927b1ca86ab 100644
--- a/pkg/compiler/lib/src/ssa/types_propagation.dart
+++ b/pkg/compiler/lib/src/ssa/types_propagation.dart
@@ -146,6 +146,9 @@ class SsaTypePropagator extends HBaseVisitor implements OptimizationPhase {
   }
 
   TypeMask visitInstruction(HInstruction instruction) {
+    if (instruction.instructionType == null) {
+      print("here");

[sra1, 2015/06/10 19:29:59]

Remove debugging code

[herhut, 2015/06/11 08:03:55]

Already removed in the cleanup patch that followed this one.

+    }
     assert(instruction.instructionType != null);
     return instruction.instructionType;
   }