Address review comments from https://chromiumcodereview.appspot.com/10454049/.

lib/compiler/implementation/ssa/builder.dart

Index: lib/compiler/implementation/ssa/builder.dart
===================================================================
--- lib/compiler/implementation/ssa/builder.dart	(revision 8142)
+++ lib/compiler/implementation/ssa/builder.dart	(working copy)
@@ -3122,7 +3122,7 @@
     // must not reuse the existing locals handler. None of the variables
     // that have been defined in the body-block will be used, but for
     // loops we will add (unnecessary) phis that will reference the body
-    // variables. This will make it look as if the variables were used
+    // variables. This makes it look as if the variables were used
     // in a non-dominated block.
     LocalsHandler savedLocals = new LocalsHandler.from(localsHandler);
     HBasicBlock enterBlock = openNewBlock();