[aes,dv] Add a cast for the byte type return of getc() function to string variable assignment

[dariuszst]

From SV LRM:

6.16.3 Getc()
function byte getc(int i);
— str.getc(i) returns the ASCII code of the ith character in str.
— If i < 0 or i >= str.len(), then str.getc(i) returns 0.

Thus the type cast should be used to assign it to string variable.

[rswarbrick]

I'm not sure this is needed. Isn't this just addressed by the last sentence here?

[danielmlynek]

Reading the SV LRM strictly getc return a byte and byte is not assignment compatible with string.
You are trying to assign byte to whole string - so error is expected.
If you would try to assign it string element like below:
s [0] = name.getc(name.len - 1);
then this would be perfectly legal.
Some tools allow to suppress such error - but it is better to just fix the code.

[rswarbrick]

Oh, that makes sense. How silly of me! It's like mixing up char * and char in C (char *my_str = 'a';)

[rswarbrick]

Thanks for the change. Annoyingly, it's failing CI because of the commit message being badly formatted. Would you mind tweaking?