Make NSString(contentsOf:usedEncoding:) tests work on macOS

- Add the NSString-UTF32-{LE,BE}-data.txt tests to the copy resources.

- Add the BOM marker 0xFEFF to the start of the comparison string.

Author: spevans

Foundation.xcodeproj/project.pbxproj

@@ -321,6 +321,8 @@
 		B90C57BC1EEEEA5A005208AE /* TestThread.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5E5835F31C20C9B500C81317 /* TestThread.swift */; };
 		B910957A1EEF237800A71930 /* NSString-UTF16-LE-data.txt in Resources */ = {isa = PBXBuildFile; fileRef = B91095781EEF237800A71930 /* NSString-UTF16-LE-data.txt */; };
 		B910957B1EEF237800A71930 /* NSString-UTF16-BE-data.txt in Resources */ = {isa = PBXBuildFile; fileRef = B91095791EEF237800A71930 /* NSString-UTF16-BE-data.txt */; };
+		B933A79E1F3055F700FE6846 /* NSString-UTF32-BE-data.txt in Resources */ = {isa = PBXBuildFile; fileRef = B933A79C1F3055F600FE6846 /* NSString-UTF32-BE-data.txt */; };
+		B933A79F1F3055F700FE6846 /* NSString-UTF32-LE-data.txt in Resources */ = {isa = PBXBuildFile; fileRef = B933A79D1F3055F600FE6846 /* NSString-UTF32-LE-data.txt */; };
 		B9974B961EDF4A22007F15B8 /* TransferState.swift in Sources */ = {isa = PBXBuildFile; fileRef = B9974B8F1EDF4A22007F15B8 /* TransferState.swift */; };
 		B9974B971EDF4A22007F15B8 /* MultiHandle.swift in Sources */ = {isa = PBXBuildFile; fileRef = B9974B901EDF4A22007F15B8 /* MultiHandle.swift */; };
 		B9974B981EDF4A22007F15B8 /* libcurlHelpers.swift in Sources */ = {isa = PBXBuildFile; fileRef = B9974B911EDF4A22007F15B8 /* libcurlHelpers.swift */; };
@@ -785,6 +787,8 @@
 		B167A6641ED7303F0040B09A /* README.md */ = {isa = PBXFileReference; lastKnownFileType = net.daringfireball.markdown; path = README.md; sourceTree = "<group>"; };
 		B91095781EEF237800A71930 /* NSString-UTF16-LE-data.txt */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; path = "NSString-UTF16-LE-data.txt"; sourceTree = "<group>"; };
 		B91095791EEF237800A71930 /* NSString-UTF16-BE-data.txt */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; path = "NSString-UTF16-BE-data.txt"; sourceTree = "<group>"; };
+		B933A79C1F3055F600FE6846 /* NSString-UTF32-BE-data.txt */ = {isa = PBXFileReference; lastKnownFileType = text; path = "NSString-UTF32-BE-data.txt"; sourceTree = "<group>"; };
+		B933A79D1F3055F600FE6846 /* NSString-UTF32-LE-data.txt */ = {isa = PBXFileReference; lastKnownFileType = text; path = "NSString-UTF32-LE-data.txt"; sourceTree = "<group>"; };
 		B9974B8F1EDF4A22007F15B8 /* TransferState.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = TransferState.swift; path = http/TransferState.swift; sourceTree = "<group>"; };
 		B9974B901EDF4A22007F15B8 /* MultiHandle.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = MultiHandle.swift; path = http/MultiHandle.swift; sourceTree = "<group>"; };
 		B9974B911EDF4A22007F15B8 /* libcurlHelpers.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = libcurlHelpers.swift; path = http/libcurlHelpers.swift; sourceTree = "<group>"; };
@@ -1402,6 +1406,8 @@
 				CE19A88B1C23AA2300B4CB6A /* NSStringTestData.txt */,
 				B91095781EEF237800A71930 /* NSString-UTF16-LE-data.txt */,
 				B91095791EEF237800A71930 /* NSString-UTF16-BE-data.txt */,
+				B933A79C1F3055F600FE6846 /* NSString-UTF32-BE-data.txt */,
+				B933A79D1F3055F600FE6846 /* NSString-UTF32-LE-data.txt */,
 				528776181BF27D9500CB0090 /* Test.plist */,
 				EA66F63B1BF1619600136161 /* NSURLTestData.plist */,
 				E1A3726E1C31EBFB0023AF4D /* NSXMLDocumentTestData.xml */,
@@ -2076,6 +2082,8 @@
 			isa = PBXResourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				B933A79E1F3055F700FE6846 /* NSString-UTF32-BE-data.txt in Resources */,
+				B933A79F1F3055F700FE6846 /* NSString-UTF32-LE-data.txt in Resources */,
 				D3A597F41C34142600295652 /* NSKeyedUnarchiver-NotificationTest.plist in Resources */,
 				528776191BF27D9500CB0090 /* Test.plist in Resources */,
 				EA66F6481BF1619600136161 /* NSURLTestData.plist in Resources */,

TestFoundation/TestNSString.swift

@@ -313,7 +313,7 @@ class TestNSString : XCTestCase {
       do {
           var encoding: UInt = 0
           let string = try NSString(contentsOf: testFileURL, usedEncoding: &encoding)
-          XCTAssertEqual(string, "NSString fromURL usedEncoding test with UTF16 BE file", "Wrong result when reading UTF16BE file")
+          XCTAssertEqual(string, "\u{FEFF}NSString fromURL usedEncoding test with UTF16 BE file", "Wrong result when reading UTF16BE file")
           XCTAssertEqual(encoding, String.Encoding.utf16BigEndian.rawValue, "Wrong encoding detected from UTF16BE file")
       } catch {
           XCTFail("Unable to init NSString from contentsOf:usedEncoding:")
@@ -329,7 +329,7 @@ class TestNSString : XCTestCase {
       do {
           var encoding: UInt = 0
           let string = try NSString(contentsOf: testFileURL, usedEncoding: &encoding)
-          XCTAssertEqual(string, "NSString fromURL usedEncoding test with UTF16 LE file", "Wrong result when reading UTF16LE file")
+          XCTAssertEqual(string, "\u{FEFF}NSString fromURL usedEncoding test with UTF16 LE file", "Wrong result when reading UTF16LE file")
           XCTAssertEqual(encoding, String.Encoding.utf16LittleEndian.rawValue, "Wrong encoding detected from UTF16LE file")
       } catch {
           XCTFail("Unable to init NSString from contentOf:usedEncoding:")
@@ -345,7 +345,7 @@ class TestNSString : XCTestCase {
       do {
          var encoding: UInt = 0
          let string = try NSString(contentsOf: testFileURL, usedEncoding: &encoding)
-         XCTAssertEqual(string, "NSString fromURL usedEncoding test with UTF32 BE file", "Wrong result when reading UTF32BE file")
+         XCTAssertEqual(string, "\u{FEFF}NSString fromURL usedEncoding test with UTF32 BE file", "Wrong result when reading UTF32BE file")
          XCTAssertEqual(encoding, String.Encoding.utf32BigEndian.rawValue, "Wrong encoding detected from UTF32BE file")
       } catch {
           XCTFail("Unable to init NSString from contentOf:usedEncoding:")
@@ -361,7 +361,7 @@ class TestNSString : XCTestCase {
       do {
          var encoding: UInt = 0
          let string = try NSString(contentsOf: testFileURL, usedEncoding: &encoding)
-         XCTAssertEqual(string, "NSString fromURL usedEncoding test with UTF32 LE file", "Wrong result when reading UTF32LE file")
+         XCTAssertEqual(string, "\u{FEFF}NSString fromURL usedEncoding test with UTF32 LE file", "Wrong result when reading UTF32LE file")
          XCTAssertEqual(encoding, String.Encoding.utf32LittleEndian.rawValue, "Wrong encoding detected from UTF32LE file")
       } catch {
           XCTFail("Unable to init NSString from contentOf:usedEncoding:")