Add clox patch

[gloria-mundi]

This adds a patch to allow LoxLox to run on clox. clox is modified to support up to 32768 constants per chunk, by encoding larger constant indices in two bytes. In addition, the stack size has been doubled to allow LoxLox to parse itself without overflowing the stack.

Performance

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
./clox sum.lox	20.6 ± 2.0	14.4	23.9	1.00
./jlox sum.lox	205.9 ± 18.3	180.0	264.5	10.02 ± 1.31
./clox lox.lox < sum.lox	1356.4 ± 20.8	1327.4	1426.8	65.99 ± 6.44
./jlox lox.lox < sum.lox	8276.7 ± 168.6	8010.6	8695.5	402.69 ± 39.67

LoxLox under clox is only about 6.5 times slower than jlox! (on this specific benchmark, on my machine)

[benhoyt]

This is brilliant -- thank you! I've added a note about running under CLox to the README and will merge this. Really well done. :-) I like the variable-sized int encoding, too.

[benhoyt]

I also added an "Update: ..." note to my article about LoxLox.