swapcontext wrapper can not be implemented in C, the stack pointer saved in
the context becomes invalid when the function returns, same as setjmp,
it must be implemented in assemble language, see discussions in PR
misc/177624.
Get the accept_mtx definitions to match up.
Merge branch 'markj-build-fixes' into markj-develop
Revert "Get the accept_mtx definitions to match up."

This reverts commit edb235044a06a033cbb090130dd2bf647ef3dbd3.

Whatever. I'll let someone else fix the build.
Merge branch 'markj-build-fixes' into markj-develop