[Issue 8063] Purity of assert's second parameter

[Nicolas Sicard]

> --- Comment #1 from bearophile_hugs at eml.cc 2012-05-08 04:12:12 
> PDT ---
> (In reply to comment #0)
>> Calling impure functions in the second parameter of an assert 
>> statement within
>> the body of a pure pure is an error, even in release mode.
>
> This is good.

Since it is allowed to call impure functions in debug blocks 
inside pure functions, I thought it would be coherent that assert 
could do the same.