emscripten: remove no longer relevant comment
This was fixed in Emscripten 1.39.16, see:
@@ -365,8 +365,7 @@ def _detect_c_or_cpp_compiler(env: 'Environment', lang: str, for_machine: Machin
# emcc requires a file input in order to pass arguments to the
# linker. It'll exit with an error code, but still print the
- # linker version. Old emcc versions ignore -Wl,--version completely,
- # however. We'll report "unknown version" in that case.
+ # linker version.
with tempfile.NamedTemporaryFile(suffix='.c') as f:
cmd = compiler + [cls.LINKER_PREFIX + "--version", f.name]
_, o, _ = Popen_safe(cmd)
