sh: Don't modify exit status when break/continue/return passes !.

This matches what would happen if  ! P  were to be replaced with
if P; then false; else true; fi.

Example:
  f() { ! return 0; }; f
Fix kenv behavior when there is no static environment

In case where there are no static kernel environment entries, the
function init_dynamic_kenv() adds an incorrect entry at position 0 of
the dynamic kernel environment. This in turn causes kenv(1) to print
and empty list even though there are dynamic entries added later.

Fix this by checking env_pos in init_dynamic_kenv() and adding dynamic
entries only if there are static entries.
Fix incorrect KASSERTs in xlpge

Fix for crash in Netlogic XLP network accelerator driver when invariants
are enabled - use correct the condition for KASSERT.