Use getMethodDescriptorByName when creating unboxing method calls

It's important that we resolve the method on the specific we're unboxing as we may immediately devirtualize the call. If we incorrectly resolve to the parent method we'll improperly devirtualize it.

PiperOrigin-RevId: 724499510

transpiler/java/com/google/j2cl/transpiler/ast/RuntimeMethods.java

@@ -17,6 +17,7 @@
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
 import static com.google.j2cl.common.StringUtils.capitalize;
 import static java.util.Arrays.asList;
 import static java.util.Arrays.stream;
@@ -689,7 +690,9 @@ public static MethodCall createUnboxingMethodCall(
       Expression expression, DeclaredTypeDescriptor boxedType) {
 
     MethodDescriptor valueMethodDescriptor =
-        boxedType.getMethodDescriptor(boxedType.toUnboxedType().getSimpleSourceName() + "Value");
+        boxedType.getMethodDescriptorByName(
+            boxedType.toUnboxedType().getSimpleSourceName() + "Value");
+    checkState(valueMethodDescriptor.getEnclosingTypeDescriptor().isSameBaseType(boxedType));
 
     return MethodCall.Builder.from(valueMethodDescriptor).setQualifier(expression).build();
   }