Explicitly pass -requirement-machine-inferred-signatures=on in a test where the GSB was wrong

Author: slavapestov

test/Constraints/generic_super_constraint.swift

@@ -1,20 +1,13 @@
-// RUN: %target-swift-frontend %s -typecheck -verify
+// RUN: %target-typecheck-verify-swift %s -requirement-machine-inferred-signatures=on
 
 class Base<T> { }
 class Derived: Base<Int> { }
 
 func foo<T>(_ x: T) -> Derived where T: Base<Int>, T: Derived {
-	// expected-warning@-1{{redundant superclass constraint 'T' : 'Base<Int>'}}
-	// expected-note@-2{{superclass constraint 'T' : 'Base<Int>' implied here}}
   return x
 }
 
-// FIXME: Should not be an error
-// expected-error@+2{{type 'U' cannot be a subclass of both 'Derived' and 'Base<T>'}}
-// expected-note@+1{{constraint conflicts with 'U' : 'Base<T>'}}
 func bar<T, U>(_ x: U, y: T) -> (Derived, Int) where U: Base<T>, U: Derived {
-  // FIXME
-  // expected-error@+1{{cannot convert return expression}}
   return (x, y)
 }