C 1.46_05: add HINT_RE_EVAL for re-eval groups

we need to set the hints, because we pregcomp now at run-time, not compile-time
fixes one of the re-eval tests #135, but not the lexical/global wontfix errors with
sv_compile_2op_is_broken()
We declare unimported constants just for the parser as 0x0
t/testc.sh 135 testcase: Eval-group not allowed at runtime