Rename function in modulo readers for v5.0.0

[domire8]

Changing the name of this function is technically API breaking change, considering that any user might have included this header and call this function in their source code. It wouldn't be ABI breaking because any compiled targets would have inlined this function and would not need to look it up from the shared library. The risk is very small since it's only used locally here, but still.

I would prefer you mark a FIXME or TODO comment to patch before a 5.0 release, either keeping the old name and calling it for the io state case (easiest) or adding a new copied and renamed function / wrapper function just for io state as a temporary workaround

Originally posted by @eeberhard in #76 (comment)