[3.12] gh-88943: Improve syntax error for non-ASCII character that follows a numerical literal (GH-109081) (#109090)

gh-88943: Improve syntax error for non-ASCII character that follows a numerical literal (GH-109081)

It now points on the invalid non-ASCII character, not on the valid numerical literal.
(cherry picked from commit b2729e93e9d73503b1fda4ea4fecd77c58909091)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>