CLSA-2026-1777558504 vim: Fix of 10 CVEs

CVE-2021-3928: in suggesttriewalk only credit a non-word-char boundary with SCORENONWORD when preword is non-empty, so spell suggestions do not read uninitialized memory behind preword. - CVE-2021-3974: in nfaregmatch NFAMARK / NFAMARKGT / NFAMARKLT, save reginput - regline and re-fetch regline...