Allow generate toString(), equals(), and hashCode() to include non-default accessors

^KT-15262 Fixed

idea/testData/codeInsight/generate/equalsWithHashCode/explicitDefaultAccessors.kt.after

@@ -8,11 +8,19 @@ class Test {
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
         if (javaClass != other?.javaClass) return false
+
+        other as Test
+
+        if (serial != other.serial) return false
+        if (name != other.name) return false
+
         return true
     }
 
     override fun hashCode(): Int {
-        return javaClass.hashCode()
+        var result = serial.hashCode()
+        result = 31 * result + name.hashCode()
+        return result
     }
 
 }