Make DescriptorArray::IsMoreGeneralThan() and DescriptorArray::Merge() compatible again.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 95b2b062866bf71c34a0a3d416e77cdfed8d5b41..224f71a840d256fa5291de968465aa494b9ba52c 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -8520,6 +8520,10 @@ bool DescriptorArray::IsMoreGeneralThan(int verbatim,
     if (details.type() == CONSTANT) {
       if (other_details.type() != CONSTANT) return false;
       if (GetValue(descriptor) != other->GetValue(descriptor)) return false;
+    } else if (details.type() == FIELD && other_details.type() == FIELD) {
+      if (!other->GetFieldType(descriptor)->NowIs(GetFieldType(descriptor))) {
+        return false;
+      }
     }
   }