[Object] Deduplicate the three createError functions

The Object library currently has three identical functions that translate a
Twine into a parser error. Until recently these functions have coexisted
peacefully, but since D110320 Clang with enabled modules is now diagnosing that
we have several definitions of `createError` in Object.

This patch just merges them all and puts them into Object's `Error.h` where the
error code for `parse_failed` is also defined which seems cleaner and unbreaks
the bots.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D111541