Improve stdin character generation

[Aaron1011]

Currently, StdinCharGenerator can only generate characters within a specified range. It would be useful to be able to specify additional characters outside of that range (e.g. \n), to allow properly solving tests/wyvern

[Tiecoon]

Currently I believe the min and Max can be set to cover the entire ascii range of 0-255. The issue with the new line I believe is that we forcefully close stdin to prevent waiting on input. Also the test case I believe doesn't check the last character anyways so it wouldn't show up as new line unless we don't close stdin like it does now.

[Tiecoon]

The default constructor is set to the ascii range of 0x20-0x75. Which does include \n it's just a byproduct of the way it's being run that the binary isn't effected by the last character.

[Aaron1011]

Isn't 0x0a the code for \n?

[Tiecoon]

Ah yeah, the stdin generator constructor currently had fields to set a min and max. You could try setting it lower on the test case but I believe it won't make a difference unless we risk a program hanging on stdin.

[Tiecoon]

It might be nice to be able to support multiple separate ranges in this case I guess

[Tiecoon]

Yeah ok I see what you mean, I think I misread the initial issue. I don't think it will fix the test case output however. Just a heads up null bytes may effect strlen and cause issues.

[twizmwazin]

The range implementation was to prevent null bytes causing short strings to be larger outliers than correct results. This could be replaced with a alternative constructor taking a Vec<u8> of all acceptable values.