Add CHECK: lines to explicitly verify some dodgy requirement signatures

Author: slavapestov

validation-test/compiler_crashers_2_fixed/0173-circular-generic-type-alias-deserialization.swift

@@ -1,10 +1,13 @@
 // RUN: %empty-directory(%t)
-// RUN: %target-build-swift -emit-module-path %t/foo.swiftmodule %s
+// RUN: %target-build-swift -emit-module-path %t/foo.swiftmodule -Xfrontend -debug-generic-signatures -Xfrontend -requirement-machine-protocol-signatures=on %s 2>&1 | %FileCheck %s
 
 public protocol P { }
 public struct X<T: P> {
   public init() { }
 }
+
+// CHECK-LABEL: main.(file).Q@
+// CHECK-NEXT: Requirement signature: <Self where Self.A : P, Self.C : Collection, Self.C.Element == X<Self.A>>
 public protocol Q {
   associatedtype A: P
   associatedtype C: Collection where C.Element == MyX

validation-test/compiler_crashers_2_fixed/sr11639.swift

@@ -1,4 +1,4 @@
-// RUN: %target-swift-frontend -emit-ir -primary-file %s
+// RUN: %target-swift-frontend -emit-ir -primary-file %s -debug-generic-signatures -requirement-machine-protocol-signatures=on 2>&1 | %FileCheck %s
 
 public protocol FooProtocol {
   associatedtype Bar
@@ -13,3 +13,6 @@ public protocol BazProtocol: FooProtocol {
   associatedtype Foo2Bar
   typealias Foo2 = Foo<Foo2Bar>
 }
+
+// CHECK-LABEL: sr11639.(file).BazProtocol@
+// CHECK-NEXT: Requirement signature: <Self where Self : FooProtocol, Self.Foo1 : FooProtocol, Self.Foo2Bar == Self.Foo1.Bar>