Merge branch 'hex-literals' of git://github.com/gsmaverick/wren into gsmaverick-hex-literals

test/number/hex_literals.wren

@@ -0,0 +1,8 @@
+var x = 0xFF
+
+IO.print(x) // expect: 255
+IO.print(x + 1) // expect: 256
+IO.print(x == 255) // expect: true
+IO.print(0x09 is Num) // expect: true
+IO.print(x is Num) // expect: true
+IO.print(-0xFF) // expect: -255

test/number/invalid_hex_literal.wren

@@ -0,0 +1 @@
+var x = 2xFF // expect error: Error at 'xFF': Expect end of file.