message: Limit recursion depth for IsUnmodified check
  * We won't inline 10 levels of statements anyway, so there's no point in
  exponentially searching for inline candidates.
diff: @@ -2086,6 +2086,14 @@ static bool IsUnmodified(SPVFunction *func, SPVInstruction *from, SPVInstruction
  return true;
  }
  + // hack - anything over 3 levels of recursion and we just bail rather than checking further.
  + static int recurse = 0;
  +
  + if(recurse > 3)
  + return false;
  +
  + recurse++;
  +
  // otherwise, recurse
  bool ret = true;
  @@ -2099,6 +2107,7 @@ static bool IsUnmodified(SPVFunction *func, SPVInstruction *from, SPVInstruction
  ret &= IsUnmodified(func, from->op->arguments[i], to);
  }
  + recurse--;
  return ret;
  }
  