log2 numeric type

[mvirts]

New numeric type that only stores the next lower power of 2

print(log2(16))
16
print(log2(19))
16
print(log2(9))
8

it would still participate in math operations like a normal integer, but would only store the exponent.

Could also introduce types in other bases (8,10,16,64)

alternate names
'sinking point' sink2
'point blank' pb2
'exponent 2' xp2
'just the point' jtp2
'mantissaless float' mf2
'one float' of2

math.log2 specialization would be easy to implement