Fix dominatedUsers for phis.

lib/compiler/implementation/ssa/nodes.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 interface HVisitor<R> {
   R visitAdd(HAdd node);
   R visitBailoutTarget(HBailoutTarget node);
   R visitBitAnd(HBitAnd node);
   R visitBitNot(HBitNot node);
   R visitBitOr(HBitOr node);
@@ skipping 957 matching lines @@
     if (usersInCurrentBlock > 0) {
       HInstruction current = otherBlock.first;
       while (current !== other) {
         if (users.contains(current)) {
           users.remove(current);
           if (--usersInCurrentBlock == 0) break;
         }
         current = current.next;
       }
     }
+    // Phis are before [other] too.

[kasperl, 2012/08/06 10:31:03]

Newline before this (to match the rest of the method). I would also consider
maintaining usersInCurrentBlock and dealing with the same way as for the other
instructions (check that it is greater than zero before running through the
phis, etc.). If not, you should add a comment that explains why that isn't
necessary.

Maybe it would be nicer if you dealt with the phis before the rest -- logically
the phis are before the first instruction in other, right?

[floitsch, 2012/08/06 14:05:27]

Done.

+    for (HPhi phi = otherBlock.phis.first; phi != null; phi = phi.next) {

[kasperl, 2012/08/06 10:31:03]

!== null

[floitsch, 2012/08/06 14:05:27]

Done.

+      users.remove(phi);
+    }
 
     return users;
   }
 
   bool isConstant() => false;
   bool isConstantBoolean() => false;
   bool isConstantNull() => false;
   bool isConstantNumber() => false;
   bool isConstantInteger() => false;
   bool isConstantString() => false;
@@ skipping 1695 matching lines @@
   HBasicBlock get start() => expression.start;
   HBasicBlock get end() {
     // We don't create a switch block if there are no cases.
     assert(!statements.isEmpty());
     return statements.last().end;
   }
 
   bool accept(HStatementInformationVisitor visitor) =>
       visitor.visitSwitchInfo(this);
 }