* lisp.h (CSET): Remove.

* lisp.h (CSET): Remove.

(set_char_table_ascii, set_char_table_defalt, set_char_table_parent)
(set_char_table_purpose): New functions,
replacing CSET.  All uses changed.  For example, replace
"CSET (XCHAR_TABLE (char_table), parent, parent);" with
"char_table_set_parent (char_table, parent);".
The old version was confusing because it used the same name
'parent' for two different things.

Fixes: debbugs:12215