int8, int16, int32

[yegor256]

Let's create new objects org.eolang.math.int8, etc. They should work exactly as int, but with smaller bitwise layout (8 bits, 16, and 32 respectively).

[yegor256]

@mximp maybe first it would be reasonable to implement them in Java with proper EO tests. Then, switch to EO, piece by piece.