Why aren't the calculations in the "mostSignificantBit" function wrapped in an "unchecked" block?

[PaulRBerg]

I can't remember why I did not wrap the calculations in the mostSignificantBit function in an unchecked block. That would definitely save a bit of gas.

It's not like the msb value can ever overflow. And the shift operation is not covered by checked arithmetic anyway.

[PaulRBerg]

I just added the unchecked block and all tests pass. I will move forward with this change.

[PaulRBerg]

Preliminary gas savings:

input: 16000000000000000000 
old: 22001 gas
new: 21907 gas

input: 5798123892292901000000000000 
old: 28034 gas
new: 27940 gas

input: 88002427921890780042122783
old: 28154
new: 27916

The gas saving is non-negligible (at least 94 gas).