Bug#6147: Traditional: Assigning a string to a numeric column has unexpected results

The problem was that when converting a string to an exact number,
rounding didn't work, because conversion didn't understand
approximate numbers notation.
Fix: a new function for string-to-number conversion was implemented,
which is aware of approxinate number notation (with decimal point
and exponent, e.g. -19.55e-1)

strings/ctype-cp932.c

@@ -5492,6 +5492,7 @@ static MY_CHARSET_HANDLER my_charset_handler=
   my_strntoull_8bit,
   my_strntod_8bit,
   my_strtoll10_8bit,
+  my_strntoull10rnd_8bit,
   my_scan_8bit
 };