[tests][SR-9425] Add regression tests for enum equatable match

Author: LucianoPAlmeida

test/SILGen/enum_equatable_witness.swift

@@ -0,0 +1,58 @@
+// RUN: %target-swift-emit-silgen -module-name main %s -verify | %FileCheck %s
+// SR-9425
+enum MyState : String {
+    case closed = "closed"
+    case opened = "opened"
+}
+
+@inline(never)
+func check_state(_ state : MyState) -> Int {
+  // CHECK: function_ref @$s4main7MyStateO21__derived_enum_equalsySbAC_ACtFZ
+  return state == .opened ? 1 : 0
+}
+
+// regular-enum.swift
+enum Regular {
+  case closed
+  case opened
+}
+
+@inline(never)
+func check_regular(_ state : Regular) -> Int {
+  // CHECK: function_ref @$s4main7RegularO21__derived_enum_equalsySbAC_ACtFZ
+  return state == .closed ? 1 : 0
+}
+
+// string-enum.swift
+enum Alphabet : String {
+  case A = "A", B = "B", C = "C", D = "D", E = "E", F = "F", G = "G", H = "H", I = "I", J = "J"
+}
+
+@inline(never)
+func check_alphabet(_ state : Alphabet) -> Int {
+  // CHECK: function_ref @$s4main8AlphabetO21__derived_enum_equalsySbAC_ACtFZ
+  return state == .E ? 1 : 0
+}
+
+@inline(never)
+func compareIt(_ state : Alphabet, _ rhs: Alphabet) -> Bool {
+  // CHECK: function_ref @$s4main8AlphabetO21__derived_enum_equalsySbAC_ACtFZ
+  return state == rhs
+}
+
+// int-enum.swift
+enum AlphabetInt : Int {
+  case A = 10, B = 100, C = 12, D = 456, E = 1, F = 3, G = 77, H = 2, I = 27, J = 42
+}
+
+@inline(never)
+func check_alphabet_int(_ state : AlphabetInt) -> Int {
+  // CHECK: function_ref @$s4main11AlphabetIntO21__derived_enum_equalsySbAC_ACtFZ
+  return state == .E ? 1 : 0
+}
+
+@inline(never)
+func compareIt(_ state : AlphabetInt, _ rhs: AlphabetInt) -> Bool {
+  // CHECK: function_ref @$s4main11AlphabetIntO21__derived_enum_equalsySbAC_ACtFZ
+  return state == rhs
+}