Remove some special case code that took care of mapping hyper to the
correct C types.

As the list of procedures that is allowed to map hyper to long is fixed
put it in the generator instead annotations in the .x files. This
results in simpler .x file parsing code.

Use macros for hyper to long assignments that perform overflow checks
when long is smaller than hyper. Map hyper to long long by default.

Suggested by Eric Blake.