KTR_EXECENV
if (KTRPOINT(p, KTR_EXECENV))
ktrexec(p, KTR_EXECENV, env_start, dp - env_start);
assert(type == KTR_EXECARGS || type == KTR_EXECENV);
#define KTRFAC_EXECENV (1<<KTR_EXECENV)
case KTR_EXECENV:
case KTR_EXECENV: