#14897: Enhance error messages of struct.pack and struct.pack_into

Patch by Matti Mäki.

diff --cc Misc/ACKS
index 3966ba67cc1f911c31fbe9910b3cc357ae04d400,a070be811c1d7f3f70581d52ed17ccec6aba48ba..1db819477a0e3ec8fe1c19acf39cf89f5ef8cc3d
--- 1/Misc/ACKS
--- 2/Misc/ACKS
+++ b/Misc/ACKS
@@@ -813,13 -738,12 +813,14 @@@ Alessandro Mour
  Pablo Mouzo
  Mher Movsisyan
  Ruslan Mstoi
 -Sjoerd Mullender
 +Michael Mulich
  Sape Mullender
 +Sjoerd Mullender
  Michael Muller
  Neil Muller
 +Louis Munro
  R. David Murray
+ Matti Mäki
  Dale Nagata
  John Nagle
  Takahiro Nakayama

diff --cc Misc/NEWS
Simple merge

diff --cc Modules/_struct.c
Simple merge