Compiler allows bogus bound for `argv` parameter to `main` (unsound)

[mattmccutchen-cci]

I imagine the standard Checked C signature for main should be something like:

int main(int argc, _Nt_array_ptr<_Nt_array_ptr<char>> argv : count(argc));

(And maybe add an environ parameter too?) But the compiler does not enforce this: it seems to accept any signature with the correct unchecked type, including one with a bogus bound for argv. The following code compiles with no warnings and gives me a segmentation fault at runtime:

#pragma CHECKED_SCOPE on

const int bogus_count = 100000000;

int main(int argc, _Nt_array_ptr<_Nt_array_ptr<char>> argv : count(bogus_count)) {
  for (int i = 0; i < bogus_count; i++) {
    argv[i] = 0;
  }
  return 0;
}