Add int before register in 1998/schweikh2

That is in main(). It works now and it might be implicit but just in
case clang ever has a problem with this it should now be satisfied.

1998/schweikh2/schweikh2.c

@@ -9,7 +9,7 @@ static volatile sig_atomic_t One;
 in??/
 t
 #line 10 ONE(O(1,1,2,6,0,6))
-main (register zero, char **ONE)
+main (register int zero, char **ONE)
 %:
 <% switch (sizeof __FILE__ < zero) case 1: return One /= zero;
 { auto one = zero = atoi (ONE<:zero-1:>);

thanks-for-fixes.md

@@ -2172,6 +2172,10 @@ interesting historical explanation and further details and fun, see the
 [historical remarks](1998/schweikh2/README.md#historical-remarks) in the
 README.md.
 
+Cody also added an `int` after `register` in `main()` in case clang decides to
+have a problem with that in the future which is not entirely out of the
+question.
+
 
 ## [1998/schweikh3](1998/schweikh3/schweikh3.c) ([README.md](1998/schweikh3/README.md]))