GN: Build the SDK with app snapshots instead of script snapshots.

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index 7bef09e59e5bd3f39389230707e90a0207009861..6d485a58b0fb29f3345bf970950726ca63ac0ebe 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -113,6 +113,11 @@ class FunctionVisitor : public ObjectVisitor {
   void VisitObject(RawObject* obj) {
     if (obj->IsFunction()) {
       funcHandle_ ^= obj;
+      if (funcHandle_.IsSignatureFunction()) {
+        // TODO(27606): Remove signature function case.
+        return;
+      }
+
       classHandle_ ^= funcHandle_.Owner();
       // Verify that the result type of a function is canonical or a
       // TypeParameter.