Implement integer operations

[ColinEberhardt]

• [x] i32.add
• [x] i32.sub
• [x] i32.mul
• [x] i32.div_u
• [x] i32.div_s - needs to throw 'integer overflow' exception
• [x] i32.or
• [x] i32.xor
• [x] i32.and
• [x] i32.rem_u
• [x] i32.rem_s
• [x] i32.shl
• [x] i32.shr_u
• [x] i32.shr_s
• [x] i32.rotl
• [x] i32.rotr
• [x] i32.clz
• [x] i32.ctz
• [x] i32.popcnt
• [x] i32.eq
• [x] i32.eqz
• [x] i32.ine
• [x] i32.ilt_u
• [x] i32.ilt_s
• [x] i32.igt_u
• [x] i32.igt_s
• [x] i32.ile_u
• [x] i32.ile_s
• [x] i32.ige_u
• [x] i32.ige_s
• [ ] i64.add
• [ ] i64.sub
• [ ] i64.mul
• [ ] i64.div_u
• [ ] i64.div_s
• [ ] i64.rem_u
• [ ] i64.rem_s
• [ ] i64.and
• [ ] i64.or
• [ ] i64.xor
• [ ] i64.shl
• [ ] i64.shr_u
• [ ] i64.shr_s
• [ ] i64.rotl
• [ ] i64.rotr
• [ ] i64.iclz
• [ ] i64.ictz
• [ ] i64.ipopcnt
• [ ] i64.ieqz
• [ ] i64.ieq
• [ ] i64.ine
• [ ] i64.ilt_u
• [ ] i64.ilt_s
• [ ] i64.igt_u
• [ ] i64.igt_s
• [ ] i64.ile_u
• [ ] i64.ile_s
• [ ] i64.ige_u
• [ ] i64.ige_s

https://webassembly.github.io/spec/core/exec/numerics.html#integer-operations