Handle generic factory constructors in kernel_impact

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

Index: pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
diff --git a/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart b/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
index cb9929afaa1e4e933021435eaa2370dabb2c15a2..4f31bb2f47ffb15b835f2c2c74209f9172d4d8c0 100644
--- a/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
+++ b/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
@@ -173,6 +173,10 @@ class KernelAstAdapter {
   DartType getDartType(ir.DartType type) {
     return type.accept(_typeConverter);
   }
+
+  List<DartType> getDartTypes(List<ir.DartType> types) {
+    return types.map(getDartType).toList();
+  }
 }
 
 class DartTypeConverter extends ir.DartTypeVisitor<DartType> {