Partial array bounds checks removal

[Brad Roberts]

bearophile wrote:
> Tim M:
>> Oh now this will never fail but you can never be too sure.<
> 
> In the last thousand years humans have invented a thing named
> "mathematics". In certain circumstances it allows you to be certain of
> some things. In some part of the programs you can use this (simple)
> mathematics and be actually certain a certain bound will not be
> exceeded. Trust me, mathematics can be marvelous :-)
> 
> Bye,
> bearophile

And in the last 30 years, compiler writers have invented optimizers.
Nearly every bit of that is in the realm of exactly what the
optimization phases of a compiler do.  So, yes, dmd, llvm, gcc.. they
all do this by design.

No need to be condescending, bearophile.

Later,
Brad