Fixed CGRect : Equatable

Fix for 2 bugs:

1.
```swift
CGRect(x: 0, y: 0, width: -5, height: -5) == CGRect(x: -5, y: -5, width: 5, height: 5)
// used to return false
// should standardize before comparison first
```

2.
```swift
let a = CGRect(x: CGFloat.infinity, y: 1, width: 2, height: 3)
let b = CGRect(x: 1, y: CGFloat.infinity, width: 2, height: 3)
a == b
// used to return false
// should return true if both `a` and `b` have any origin's value set to +∞
```

Author: bubski

Foundation/NSGeometry.swift

@@ -399,7 +399,11 @@ extension CGRect {
 
 extension CGRect: Equatable {
     public static func ==(lhs: CGRect, rhs: CGRect) -> Bool {
-        return lhs.origin == rhs.origin && lhs.size == rhs.size
+        if lhs.isNull && rhs.isNull { return true }
+
+        let r1 = lhs.standardized
+        let r2 = rhs.standardized
+        return r1.origin == r2.origin && r1.size == r2.size
     }
 }
 

TestFoundation/TestNSGeometry.swift

@@ -58,6 +58,7 @@ class TestNSGeometry : XCTestCase {
             ("test_CGRect_IsNull", test_CGRect_IsNull),
             ("test_CGRect_IsInfinite", test_CGRect_IsInfinite),
             ("test_CGRect_IsEmpty", test_CGRect_IsEmpty),
+            ("test_CGRect_Equatable", test_CGRect_Equatable),
             ("test_CGRect_CalculatedGeometricProperties", test_CGRect_CalculatedGeometricProperties),
             ("test_CGRect_Standardized", test_CGRect_Standardized),
             ("test_CGRect_Integral", test_CGRect_Integral),
@@ -307,6 +308,37 @@ class TestNSGeometry : XCTestCase {
         XCTAssertFalse(CGRect.infinite.isEmpty)
     }
 
+    func test_CGRect_Equatable() {
+        XCTAssertEqual(CGRect(x: 10, y: 20, width: 30, height: 40), CGRect(x: 10, y: 20, width: 30, height: 40))
+        XCTAssertEqual(CGRect(x: -10, y: -20, width: -30, height: -40), CGRect(x: -10, y: -20, width: -30, height: -40))
+        XCTAssertEqual(CGRect(x: -10, y: -20, width: 30, height: 40), CGRect(x: 20, y: 20, width: -30, height: -40))
+
+        XCTAssertNotEqual(CGRect(x: 10, y: 20, width: 30, height: 40), CGRect(x: 10, y: 20, width: 30, height: -40))
+        XCTAssertNotEqual(CGRect(x: 10, y: 20, width: 30, height: 40), CGRect(x: 10, y: 20, width: -30, height: 40))
+        XCTAssertNotEqual(CGRect(x: 10, y: 20, width: 30, height: 40), CGRect(x: 10, y: -20, width: 30, height: 40))
+        XCTAssertNotEqual(CGRect(x: 10, y: 20, width: 30, height: 40), CGRect(x: -10, y: 20, width: 30, height: 40))
+
+        XCTAssertEqual(CGRect.infinite, CGRect.infinite)
+        XCTAssertEqual(CGRect.null, CGRect.null)
+        XCTAssertNotEqual(CGRect.infinite, CGRect.null)
+
+        var r1 = CGRect.null
+        r1.size = CGSize(width: 20, height: 20)
+        XCTAssertEqual(r1, CGRect.null)
+
+        var r2 = CGRect.null
+        r2.origin.x = 20
+        XCTAssertEqual(r2, CGRect.null)
+
+        var r3 = CGRect.null
+        r3.origin.y = 20
+        XCTAssertEqual(r3, CGRect.null)
+
+        var r4 = CGRect.null
+        r4.origin = CGPoint(x: 10, y: 20)
+        XCTAssertNotEqual(r4, CGRect.null)
+    }
+
     func test_CGRect_CalculatedGeometricProperties() {
         let ε = CGFloat(0.00001)