bpo-44180: Report generic syntax errors in the furthest position reached in the first parser pass (GH-26253) (GH-26281)

(cherry picked from commit b51081c1a8cf01b92ba0692173e1b9274a57f455)

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index aefdd7b..5fb651f 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -213,6 +213,7 @@ def testSyntaxErrorOffset(self):
         check('[file for str(file) in []\n])', 2, 2)
         check('[\nfile\nfor str(file)\nin\n[]\n]', 3, 5)
         check('[file for\n str(file) in []]', 2, 2)
+        check("ages = {'Alice'=22, 'Bob'=23}", 1, 16)
 
         # Errors thrown by compile.c
         check('class foo:return 1', 1, 11)