Fix negated literal/end of string handling.
Fix negated literal/end of string handling.

Fixes another of the t/p5regex failures on the MoarVM backend.

cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp