Test for \s matching CRLF when scalar matching (#648)

Author: natecook1000

Tests/RegexTests/UTS18Tests.swift

@@ -286,6 +286,9 @@ extension UTS18Tests {
  // Test \v - vertical space
  lines = lineInput.matches(of: regex(#"\d{2}\v^"#).anchorsMatchLineEndings())
  XCTAssertEqual(lines.count, 11)
+ // Test \s - whitespace
+ lines = lineInput.matches(of: regex(#"\d{2}\s^"#).anchorsMatchLineEndings())
+ XCTAssertEqual(lines.count, 11)
  // Test anchors as line boundaries
  lines = lineInput.matches(of: regex(#"^\d{2}$"#).anchorsMatchLineEndings())
  XCTAssertEqual(lines.count, 12)
@@ -301,6 +304,10 @@ extension UTS18Tests {
  lines = lineInput.matches(
  of: regex(#"\d{2}\v(?=\d)"#).matchingSemantics(.unicodeScalar).anchorsMatchLineEndings())
  XCTAssertEqual(lines.count, 10)
+ // Unicode scalar semantics - \s matches all except for \r\n sequence
+ lines = lineInput.matches(
+ of: regex(#"\d{2}\s(?=\d)"#).matchingSemantics(.unicodeScalar).anchorsMatchLineEndings())
+ XCTAssertEqual(lines.count, 10)
 
  // Does not contain an empty line
  XCTAssertFalse(lineInput.contains(regex(#"^$"#)))