Change dart2js to follow the new spec on the equality operator.

lib/compiler/implementation/ssa/builder.dart

Index: lib/compiler/implementation/ssa/builder.dart
diff --git a/lib/compiler/implementation/ssa/builder.dart b/lib/compiler/implementation/ssa/builder.dart
index fc61e895948e62db2c91dfb0c2b1a5d3864fd6af..4e4ee623b2a04df45becbaa193d657b61e7f52ff 100644
--- a/lib/compiler/implementation/ssa/builder.dart
+++ b/lib/compiler/implementation/ssa/builder.dart
@@ -97,10 +97,6 @@ class Interceptors {
     return compiler.findHelper(const SourceString('indexSet'));
   }
 
-  Element getEqualsNullInterceptor() {
-    return compiler.findHelper(const SourceString('eqNull'));
-  }
-
   Element getExceptionUnwrapper() {
     return compiler.findHelper(const SourceString('unwrapException'));
   }