[CSSolver] Don't skip generic overloads when non-generic one has SK_UserConversion

In cases where matched concrete overload used a bridging, CF*, or
`AnyHashable` conversion, let's attempt generic overload choices
as well because one of them could produce a better solution e.g.
`RawRepresentable` for `==` where underlying type conforms to `Equatable`
has a better generic match than `(AnyHashable, AnyHashable) -> Bool`.

Resolves: rdar://95992916

Author: xedin

lib/Sema/CSStep.h

@@ -702,10 +702,11 @@ class DisjunctionStep final : public BindingStep<DisjunctionChoiceProducer> {
     // non-generic score indicates that there were no forced
     // unwrappings of optional(s), no unavailable overload
     // choices present in the solution, no fixes required,
-    // and there are no non-trivial function conversions.
+    // and there are no non-trivial user or function conversions.
     auto &score = BestNonGenericScore->Data;
     return (score[SK_ForceUnchecked] == 0 && score[SK_Unavailable] == 0 &&
-            score[SK_Fix] == 0 && score[SK_FunctionConversion] == 0);
+            score[SK_Fix] == 0 && score[SK_UserConversion] == 0 &&
+            score[SK_FunctionConversion] == 0);
   }
 
   /// Attempt to apply given disjunction choice to constraint system.

test/Constraints/anyhashable_and_operator_filtering.swift

@@ -0,0 +1,29 @@
+// RUN: %target-swift-emit-silgen %s -verify | %FileCheck %s
+
+// rdar://95992916 - SILGen crash due to incorrect overload pick for `==`
+
+enum E : String {
+case a
+case b
+}
+
+protocol P : AnyObject {
+  var prop: E { get }
+}
+
+func test(arr: [any P]) {
+  _ = arr.map {
+    let v = (a: $0.prop, b: $0.prop)
+    switch v {
+    case let (a, b) where a == b: break
+    default: break
+    }
+  }
+}
+
+// CHECK: sil private [ossa] @$s34anyhashable_and_operator_filtering4test3arrySayAA1P_pG_tFyAaD_pXEfU_
+// CHECK: [[LHS_ARG:%.*]] = alloc_stack $E
+// CHECK: [[RHS_ARG:%.*]] = alloc_stack $E
+// CHECK: function_ref == infix<A>(_:_:)
+// CHECK-NEXT: [[GENERIC_OP:%.*]] = function_ref @$ss2eeoiySbx_xtSYRzSQ8RawValueRpzlF : $@convention(thin) <τ_0_0 where τ_0_0 : RawRepresentable, τ_0_0.RawValue : Equatable> (@in_guaranteed τ_0_0, @in_guaranteed τ_0_0) -> Bool
+// CHECK-NEXT: apply [[GENERIC_OP]]<E>([[LHS_ARG]], [[RHS_ARG]])