NFC: Add basic -print-ast tests for derived hashable/equatable conformances.

Author: tshortli

test/decl/enum/derived_hashable_equatable.swift

@@ -0,0 +1,92 @@
+// RUN: %target-swift-frontend -print-ast %s | %FileCheck %s
+
+// CHECK-LABEL: internal enum Simple : Hashable
+enum Simple: Hashable {
+  // CHECK:        case a
+  case a
+  // CHECK:        case b
+  case b
+
+  // CHECK:        @_implements(Equatable, ==(_:_:)) internal static func __derived_enum_equals(_ a: Simple, _ b: Simple) -> Bool {
+  // CHECK-NEXT:     private var index_a: Int
+  // CHECK-NEXT:     switch a {
+  // CHECK-NEXT:     case .a:
+  // CHECK-NEXT:       index_a = 0
+  // CHECK-NEXT:     case .b:
+  // CHECK-NEXT:       index_a = 1
+  // CHECK-NEXT:     }
+  // CHECK-NEXT:     private var index_b: Int
+  // CHECK-NEXT:     switch b {
+  // CHECK-NEXT:     case .a:
+  // CHECK-NEXT:       index_b = 0
+  // CHECK-NEXT:     case .b:
+  // CHECK-NEXT:       index_b = 1
+  // CHECK-NEXT:     }
+  // CHECK-NEXT:     return index_a == index_b
+  // CHECK-NEXT:   }
+
+  // CHECK:        internal func hash(into hasher: inout Hasher) {
+  // CHECK-NEXT:     private var discriminator: Int
+  // CHECK-NEXT:     switch self {
+  // CHECK-NEXT:     case .a:
+  // CHECK-NEXT:       discriminator = 0
+  // CHECK-NEXT:     case .b:
+  // CHECK-NEXT:       discriminator = 1
+  // CHECK-NEXT:     }
+  // CHECK-NEXT:     hasher.combine(discriminator)
+  // CHECK-NEXT:   }
+
+  // CHECK:        internal var hashValue: Int {
+  // CHECK-NEXT:     get {
+  // CHECK-NEXT:       return _hashValue(for: self)
+  // CHECK-NEXT:     }
+  // CHECK-NEXT:   }
+}
+
+// CHECK-LABEL: internal enum HasAssociatedValues : Hashable
+enum HasAssociatedValues: Hashable {
+  // CHECK:        case a(Int)
+  case a(Int)
+  // CHECK:        case b(String)
+  case b(String)
+  // CHECK:        case c
+  case c
+
+  // CHECK:        internal func hash(into hasher: inout Hasher) {
+  // CHECK-NEXT:     switch self {
+  // CHECK-NEXT:     case .a(let a0):
+  // CHECK-NEXT:       hasher.combine(0)
+  // CHECK-NEXT:       hasher.combine(a0)
+  // CHECK-NEXT:     case .b(let a0):
+  // CHECK-NEXT:       hasher.combine(1)
+  // CHECK-NEXT:       hasher.combine(a0)
+  // CHECK-NEXT:     case .c:
+  // CHECK-NEXT:       hasher.combine(2)
+  // CHECK-NEXT:     }
+  // CHECK-NEXT:   }
+
+  // CHECK:        @_implements(Equatable, ==(_:_:)) internal static func __derived_enum_equals(_ a: HasAssociatedValues, _ b: HasAssociatedValues) -> Bool {
+  // CHECK-NEXT:     switch (a, b) {
+  // CHECK-NEXT:     case (.a(let l0), .a(let r0)):
+  // CHECK-NEXT:       guard l0  r0 else {
+  // CHECK-NEXT:         return false
+  // CHECK-NEXT:       }
+  // CHECK-NEXT:       return true
+  // CHECK-NEXT:     case (.b(let l0), .b(let r0)):
+  // CHECK-NEXT:       guard l0  r0 else {
+  // CHECK-NEXT:         return false
+  // CHECK-NEXT:       }
+  // CHECK-NEXT:       return true
+  // CHECK-NEXT:     case (.c, .c):
+  // CHECK-NEXT:       return true
+  // CHECK-NEXT:     default:
+  // CHECK-NEXT:       return false
+  // CHECK-NEXT:     }
+  // CHECK-NEXT:   }
+
+  // CHECK:        internal var hashValue: Int {
+  // CHECK-NEXT:     get {
+  // CHECK-NEXT:       return _hashValue(for: self)
+  // CHECK-NEXT:     }
+  // CHECK-NEXT:   }
+}