Support non-speculative type propagation.

frog/leg/ssa/nodes.dart

Index: frog/leg/ssa/nodes.dart
===================================================================
--- frog/leg/ssa/nodes.dart	(revision 5905)
+++ frog/leg/ssa/nodes.dart	(working copy)
@@ -842,26 +842,6 @@
   // inserted to make sure the users get the right type in.
   bool hasExpectedType() => false;
 
-  // Re-compute and update the type of the instruction. Returns
-  // whether or not the type was changed.
-  bool updateType() {
-    if (type.isConflicting()) return false;
-    HType newType = computeType();
-    HType desiredType = computeDesiredType();
-    HType combined = newType.combine(desiredType);
-    if (combined.isKnown()) newType = combined;
-
-    bool changed = (type != newType);
-    if (type.isUnknown()) {
-      type = newType;
-      return changed;
-    } else if (changed) {
-      type = type.combine(newType);
-      return changed;
-    }
-    return false;
-  }
-
   bool isInBasicBlock() => block !== null;
 
   String inputsToString() {
@@ -1800,12 +1780,6 @@
     return true;
   }
 
-  void setInitialTypeForLoopPhi() {
-    assert(block.isLoopHeader());
-    assert(type.isUnknown());
-    type = inputs[0].type;
-  }
-
   bool isLogicalOperator() => logicalOperatorType != IS_NOT_LOGICAL_OPERATOR;
 
   String logicalOperator() {