Unbreak -bareword under strict+integer

Commit 077da62ff9 was not supposed to change behaviour, but only
remove logic rendered unnecessary two commits earlier in 1c2b3fd6f10.

But the special stricture exception for negation was in the same func-
tion (S_op_integerize) which applied it to OP_NEGATE, but now needed
to apply it to OP_I_NEGATE, too.