Remove access for jClass in UtMockFieldInfo

Author: CaelmBleidd

utbot-framework/src/main/kotlin/org/utbot/engine/Mocks.kt

@@ -203,12 +203,18 @@ class Mocker(
                 return false
             }
 
+            val sootField = sootDeclaringClass.getFieldByName(mockInfo.fieldId.name)
+            val sootFieldType = sootField.type
+
             return when {
-                declaringClass.packageName.startsWith("java.lang") -> false
-                !mockInfo.fieldId.type.isRefType -> false  // mocks are allowed for ref fields only
-                else -> return strategy.eligibleToMock(mockInfo.fieldId.type, classUnderTest) // if we have a field with Integer type, we should not mock it
+                sootDeclaringClass.packageName.startsWith("java.lang") -> false
+                sootFieldType !is RefType -> false  // mocks are allowed for ref fields only
+                else -> strategy.eligibleToMock(sootFieldType.id, classUnderTest) // if we have a field with Integer type, we should not mock it
             }
         }
+
+        // Note that eligibleToMock can use information retrieved from jClass
+        // Therefore, such classes should be already processed at this point
         return strategy.eligibleToMock(type.id, classUnderTest) // strategy to decide
     }