Add support for compiling Dart via the FE in dart2js.

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

Index: pkg/compiler/lib/src/ssa/type_builder.dart
diff --git a/pkg/compiler/lib/src/ssa/type_builder.dart b/pkg/compiler/lib/src/ssa/type_builder.dart
index cb39ed6c6d5ef5176de066fe497fc77e7900395d..18cc72a8a23f2b8e18645511f289c2ac35de80dc 100644
--- a/pkg/compiler/lib/src/ssa/type_builder.dart
+++ b/pkg/compiler/lib/src/ssa/type_builder.dart
@@ -165,8 +165,7 @@ class TypeBuilder {
   /// Check that [type] is valid in the context of `localsHandler.contextClass`.
   /// This should only be called in assertions.
   bool assertTypeInContext(DartType type, [Spannable spannable]) {
-    if (builder.compiler.options.useKernel) return true;
-    if (builder.compiler.options.loadFromDill) return true;
+    if (builder.compiler.options.useKernelInSsa) return true;
     ClassEntity contextClass = DartTypes.getClassContext(type);
     assert(
         contextClass == null ||