[NI] Make subtyping algorithm more robust to error types

During subtyping/incorporation we transform types (e.g. changing nullability,
 form of the type) and, basically, we're doing this to some FIXPOINT.
 It's important that we use `KotlinType.hashCode()` to compare types, but
 for error types hashCode is a hashCode of its supertype and, for example,
 `makeNullableAsSpecified` method recreate type every time. So, we continue
 to generate new constraints and we'll never stop incorporation algorithm

compiler/testData/diagnostics/tests/delegatedProperty/inference/genericMethods.kt

@@ -1,10 +1,9 @@
 // !DIAGNOSTICS: -UNUSED_PARAMETER
-// !WITH_NEW_INFERENCE
 // NI_EXPECTED_FILE
 import kotlin.reflect.KProperty
 
 var a: Int by A()
-var a1 by <!OI;DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE, DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>A()<!>
+var a1 by <!DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE, DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>A()<!>
 
 var b: Int by B()