- Add addo_(i|u)128, subo_(i|u)128, mulo_(i|u)128, - Move zig_shlo_(i|u)128 into common code - Fixup zig_shls_i128 passing rhs as 128
- Add addo_(i|u)128, subo_(i|u)128, mulo_(i|u)128, - Move zig_shlo_(i|u)128 into common code - Fixup zig_shls_i128 passing rhs as 128