[Toybox] test.sh: Don't override "C" command path in TEST_HOST if it's set

[Rob Landley]

On 3/24/24 18:40, Rob Landley wrote:
>> Also, different command names, there's a dozen different vi implementations and 
>> only a few have the name "vi". This is true for some other commands as well
> 
> I've been doing:
> 
>   mkdir sub
>   ln -s $(which potato) sub/vi
>   PATH=$PWD/sub:$PATH make tests
> 
> Comes up a bit already, such as testing toybox tar --xform which requires toybox
> sed, and thus even the standalone test skips those unless you put toybox sed in
> the $PATH.
> 
> In theory you could PATH=$PWD/sub:$PATH TEST_HOST=1 make test_vi above, in which
> case "C" should wind up pointing into sub...

P.S. I don't want to commit to there still BEING a "C" a year from now. That's
an internal implementation detail, not an API.

Rob