Constraint incorporation

In a constraint system a new bound is incorporated:
all new constrains that can be derived from it
(and from existing ones) are added

compiler/testData/diagnostics/tests/resolve/nestedCalls/kt7597.kt

@@ -1,10 +1,8 @@
-// !CHECK_TYPE
-
 interface Inv<I>
 
 fun <S, T: S> Inv<T>.reduce2(): S = null!!
 
 fun test(a: Inv<Int>): Int {
-    val b = 1 <!OVERLOAD_RESOLUTION_AMBIGUITY!>+<!> a.reduce2()
-    return <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>b<!>
+    val b = 1 + a.reduce2()
+    return b
 }