This could lead to problem when simplehash.h is used to define two
different types of hashtable visible in the same translation unit.
Reported-By: Josh Soref
Discussion: https://postgr.es/m/CACZqfqCC7WdBAY=rQePb9-qW1rjdaTdHsV5KoVejHkDb6qrtOg@mail.gmail.com
#undef SH_STATUS
#undef SH_STATUS_EMPTY
#undef SH_STATUS_IN_USE
-#undef SH_ITERTOR
+#undef SH_ITERATOR
/* external function names */
#undef SH_CREATE