bpo-40985: Show correct SyntaxError text when last line has a LINECONT (GH-20888)


When a file ends with a line that contains a line continuation character
the text of the emitted SyntaxError is empty, contrary to the old
parser, where the error text contained the text of the last line.
(cherry picked from commit 113e2b0a07c72c0d5e3489076afb14f6b3ad1049)

Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
3 files changed