[test] StdlibUnittest: Add missing hash(into:) implementations

Author: lorentey

stdlib/private/StdlibCollectionUnittest/MinimalCollections.swift

@@ -305,8 +305,8 @@ public struct _CollectionState : Equatable, Hashable {
     }
   }
 
-  public var hashValue: Int {
-    return _id.hashValue
+  public func hash(into hasher: inout Hasher) {
+    hasher.combine(_id)
   }
 }
 

stdlib/private/StdlibUnicodeUnittest/Collation.swift

@@ -181,42 +181,11 @@ let ducetExtractData: [CollationTableEntry] = [
   CollationTableEntry([0xE01EF], [0x0000_0000_0000], "VARIATION SELECTOR-256"),
 ]
 
-public struct HashableArray<Element : Hashable> : Hashable {
-  internal var _elements: [Element]
-
-  public init(_ elements: [Element]) {
-    _elements = elements
-  }
-
-  public var hashValue: Int {
-    // FIXME: this is a bad approach to combining hash values.
-    var result = 0
-    for x in _elements {
-      result ^= x.hashValue
-      result = result &* 997
-    }
-    return result
-  }
-}
-
-public func == <Element>(
-  lhs: HashableArray<Element>,
-  rhs: HashableArray<Element>
-) -> Bool {
-  return lhs._elements.elementsEqual(rhs._elements)
-}
-
-extension HashableArray : ExpressibleByArrayLiteral {
-  public init(arrayLiteral elements: Element...) {
-    self._elements = elements
-  }
-}
-
-let ducetExtract: [HashableArray<Unicode.Scalar> : CollationTableEntry] = {
+let ducetExtract: [[Unicode.Scalar]: CollationTableEntry] = {
   () in
-  var result: [HashableArray<Unicode.Scalar> : CollationTableEntry] = [:]
+  var result: [[Unicode.Scalar]: CollationTableEntry] = [:]
   for entry in ducetExtractData {
-    result[HashableArray(entry.scalars)] = entry
+    result[entry.scalars] = entry
   }
   return result
 }()
@@ -232,7 +201,7 @@ extension String {
   internal var _collationElements: [UInt64] {
     var result: [UInt64] = []
     for us in self.unicodeScalars {
-      let scalars: HashableArray<Unicode.Scalar> = [us]
+      let scalars: [Unicode.Scalar] = [us]
       let collationElements = ducetExtract[scalars]!.collationElements
       if collationElements[0] != 0 {
         result += collationElements

stdlib/private/StdlibUnittest/LifetimeTracked.swift

@@ -51,6 +51,9 @@ extension LifetimeTracked : Hashable {
   public var hashValue: Int {
     return value
   }
+  public func hash(into hasher: inout Hasher) {
+    hasher.combine(value)
+  }
 }
 
 extension LifetimeTracked : Strideable {

stdlib/private/StdlibUnittest/StdlibCoreExtras.swift

@@ -110,14 +110,20 @@ public func <=> <T: Comparable>(lhs: T, rhs: T) -> ExpectedComparisonResult {
 }
 
 public struct TypeIdentifier : Hashable, Comparable {
+  public var value: Any.Type
+
   public init(_ value: Any.Type) {
     self.value = value
   }
 
   public var hashValue: Int { return objectID.hashValue }
-  public var value: Any.Type
-  
-  internal var objectID : ObjectIdentifier { return ObjectIdentifier(value) }
+  public func hash(into hasher: inout Hasher) {
+    hasher.combine(objectID)
+  }
+
+  internal var objectID : ObjectIdentifier {
+    return ObjectIdentifier(value)
+  }
 }
 
 public func < (lhs: TypeIdentifier, rhs: TypeIdentifier) -> Bool {

stdlib/private/StdlibUnittest/StringConvertible.swift

@@ -65,6 +65,10 @@ public struct CustomPrintableValue
     return value.hashValue
   }
 
+  public func hash(into hasher: inout Hasher) {
+    hasher.combine(value)
+  }
+
   public typealias Stride = Int
 
   public func distance(to other: CustomPrintableValue) -> Stride {