[Foundation] improve hashing of NSRanges to collide less in reasonable values (and use the length too)

Author: phausler

stdlib/public/SDK/Foundation/NSRange.swift

@@ -13,8 +13,12 @@
 @_exported import Foundation // Clang module
 
 extension NSRange : Hashable {
-    public var hashValue: Int { 
-        return Int(bitPattern: UInt(location) ^ UInt(location))
+    public var hashValue: Int {
+#if arch(i386) || arch(arm)
+        return Int(bitPattern: (UInt(bitPattern: location) | (UInt(bitPattern: length) << 16)))
+#elseif arch(x86_64) || arch(arm64)
+        return Int(bitPattern: (UInt(bitPattern: location) | (UInt(bitPattern: length) << 32)))
+#endif
     }
 
     public static func==(_ lhs: NSRange, _ rhs: NSRange) -> Bool {