[CHANGES]
- Defined XPK_KEYWORD, a better version of XPK_LITERAL for
keyword-like tokens
- Defined XPK_ARITHEXPR, a higher-precedence version of XPK_TERMEXPR
- Defined XPK_ARGSCOPE, a variant of XPK_PARENSCOPE where the parens
themselves are optional
- Undocument the old XPK_STRING token type
[BUGFIXES]
- Fixes for bugs that affect -DDEBUGGING-enabled perls
- Remember to clear OPf_KIDS when stealing the op_first of a
LISTOP (RT142770)
- Don't call cv_clone() at compiletime when unit testing; generate
an OP_ANONCODE instead (RT142771)
- Remember to clear OPf_KIDS when stealing the op_first of a