Merge pull request #85357 from slavapestov/workaround-rdar160649141

IRGen: Terrible workaround for problem in searchNominalTypeMetadata()

test/IRGen/fulfillment_map_key_equality.swift

@@ -0,0 +1,44 @@
+// RUN: %target-swift-frontend -emit-ir %s -enable-library-evolution | %FileCheck %s
+
+// FIXME: We just need to adjust the check line below, there's no inherent
+// reason for this not to be tested on wasm.
+// UNSUPPORTED: CPU=wasm32
+
+// rdar://160649141
+
+public protocol P1 {}
+
+public protocol P2 {
+  associatedtype A1
+}
+
+public protocol P5 {
+  associatedtype A2: P2
+}
+
+public protocol P3 where A4.A1 == A3.A2.A1 {
+  associatedtype A3: P5
+  associatedtype A4: P2
+
+  var x: Int { get }
+}
+
+public protocol P6: P3 {}
+
+public protocol P4 {
+  associatedtype A4: P2
+}
+
+public struct G1<A1>: P2 {}
+
+public struct G2<A2: P2>: P5  {}
+
+public struct G3<T: P6 & P4>: P3 where T.A4.A1: P1 {
+  public typealias A4 = G1<T.A3.A2.A1>
+  public typealias A3 = G2<T.A3.A2>
+
+  // Make sure this witness thunk doesn't have any additional bogus parameters.
+
+  // CHECK-LABEL: define internal swiftcc i64 @"$s28fulfillment_map_key_equality2G3VyxGAA2P3A2aEP1xSivgTW"(ptr noalias swiftself captures(none) %0, ptr %Self, ptr %SelfWitnessTable) {{.*}} {
+  public var x: Int { fatalError() }
+}