[stdlib] Add missing 10.10 NSString APIs.

containsString and localizedCaseInsensitiveContainsString were
introduced in 10.10, release-noted, but never
documented (<rdar://22236574>), so we missed them.

Fixes <rdar://18776075> String.containsString doesn't work in Swift

Swift SVN r31152

stdlib/public/SDK/Foundation/NSStringAPI.swift

@@ -1601,5 +1601,46 @@ extension String {
   ) -> String? {
     return _ns.stringByApplyingTransform(transform, reverse: reverse)
   }
+
+  //===--- From the 10.10 release notes; not in public documentation ------===//
+  // No need to make these unavailable on earlier OSes, since they can
+  // forward trivially to rangeOfString.
+
+  /// Returns `true` iff `other` is non-empty and contained within
+  /// `self` by case-sensitive, non-literal search.
+  ///
+  /// Equivalent to `self.rangeOfString(other) != nil`
+  @warn_unused_result
+  public func containsString(other: String) -> Bool {
+    let r = self.rangeOfString(other) != nil
+    if #available(OSX 10.10, iOS 8.0, *) {
+      _sanityCheck(r == _ns.containsString(other))
+    }
+    return r
+  }
+  
+  /// Returns `true` iff `other` is non-empty and contained within
+  /// `self` by case-insensitive, non-literal search, taking into
+  /// account the current locale.
+  ///
+  /// Locale-independent case-insensitive operation, and other needs,
+  /// can be achieved by calling
+  /// `rangeOfString(_:options:_,range:_locale:_)`.
+  ///
+  /// Equivalent to
+  ///
+  ///     self.rangeOfString(
+  ///       other, options: .CaseInsensitiveSearch,
+  ///       locale: NSLocale.currentLocale()) != nil
+  @warn_unused_result
+  public func localizedCaseInsensitiveContainsString(other: String) -> Bool {
+    let r = self.rangeOfString(
+      other, options: .CaseInsensitiveSearch, locale: NSLocale.currentLocale()
+    ) != nil
+    if #available(OSX 10.10, iOS 8.0, *) {
+      _sanityCheck(r == _ns.localizedCaseInsensitiveContainsString(other))
+    }
+    return r
+  }
 }
 

test/1_stdlib/NSStringAPI.swift

@@ -1176,6 +1176,62 @@ NSStringAPIs.test("rangeOfString(_:options:range:locale:)") {
   }
 }
 
+NSStringAPIs.test("containsString(_:)") {
+  withOverriddenNSLocaleCurrentLocale("en") { () -> () in
+    expectFalse("".containsString(""))
+    expectFalse("".containsString("a"))
+    expectFalse("a".containsString(""))
+    expectFalse("a".containsString("b"))
+    expectTrue("a".containsString("a"))
+    expectFalse("a".containsString("A"))
+    expectFalse("A".containsString("a"))
+    expectFalse("a".containsString("a\u{0301}"))
+    expectTrue("a\u{0301}".containsString("a\u{0301}"))
+    expectFalse("a\u{0301}".containsString("a"))
+    expectTrue("a\u{0301}".containsString("\u{0301}"))
+    expectFalse("a".containsString("\u{0301}"))
+
+    expectFalse("i".containsString("I"))
+    expectFalse("I".containsString("i"))
+    expectFalse("\u{0130}".containsString("i"))
+    expectFalse("i".containsString("\u{0130}"))
+
+    return ()
+  }
+
+  withOverriddenNSLocaleCurrentLocale("tr") {
+    expectFalse("\u{0130}".containsString("ı"))
+  }
+}
+
+NSStringAPIs.test("localizedCaseInsensitiveContainsString(_:)") {
+  withOverriddenNSLocaleCurrentLocale("en") { () -> () in
+    expectFalse("".localizedCaseInsensitiveContainsString(""))
+    expectFalse("".localizedCaseInsensitiveContainsString("a"))
+    expectFalse("a".localizedCaseInsensitiveContainsString(""))
+    expectFalse("a".localizedCaseInsensitiveContainsString("b"))
+    expectTrue("a".localizedCaseInsensitiveContainsString("a"))
+    expectTrue("a".localizedCaseInsensitiveContainsString("A"))
+    expectTrue("A".localizedCaseInsensitiveContainsString("a"))
+    expectFalse("a".localizedCaseInsensitiveContainsString("a\u{0301}"))
+    expectTrue("a\u{0301}".localizedCaseInsensitiveContainsString("a\u{0301}"))
+    expectFalse("a\u{0301}".localizedCaseInsensitiveContainsString("a"))
+    expectTrue("a\u{0301}".localizedCaseInsensitiveContainsString("\u{0301}"))
+    expectFalse("a".localizedCaseInsensitiveContainsString("\u{0301}"))
+
+    expectTrue("i".localizedCaseInsensitiveContainsString("I"))
+    expectTrue("I".localizedCaseInsensitiveContainsString("i"))
+    expectFalse("\u{0130}".localizedCaseInsensitiveContainsString("i"))
+    expectFalse("i".localizedCaseInsensitiveContainsString("\u{0130}"))
+
+    return ()
+  }
+
+  withOverriddenNSLocaleCurrentLocale("tr") {
+    expectFalse("\u{0130}".localizedCaseInsensitiveContainsString("ı"))
+  }
+}
+
 NSStringAPIs.test("localizedStandardContainsString(_:)") {
   if #available(OSX 10.11, iOS 9.0, *) {
     withOverriddenNSLocaleCurrentLocale("en") { () -> () in