If the semantics of 'while (true)' was "will crash the program after an implementation-defined but often fairly low number of iterations", I would stop using 'while (true)'.
Having said that the standards give way too much leeway for the limits, so a conforming implementation might have arbitrary limits for loops as well (at least in C++, I'm not that familiar with the C standard's wording).
But also, I wouldn't rely on a compiler to remove empty 'while (true)' loops.
Both languages continue to have examples of slightly more complicated loops that can be assumed to terminate in the absence of side effects, but `while(true)` isn't one of those any longer.
If you used an in-place sort algorithm and observed memory requirements that scale super-linearly with the size of the input, you would think the semantics of the program were changed.
In languages with such tail call guarantees, tail recursion _is_ a loop. It semantically encodes constant space complexity.