Sure, that sort of language-specific idiosyncrasy must be dealt with in the compiler's front-end. In TFA's C example, consider that their loop

  while (i <= x) {
      // ...
  }

just needs a slight transformation to

  while (1) {
      if (i > x)
          break;
      // ...
  }

and C11's special permission does not apply any more since the controlling expression has become constant.

Analyzes and optimizations in compiler backends often normalize those two loops to a common representation (e.g. control-flow graph) at some point, so whatever treatment that sees them differently must happen early on.