Revert "Revert "kernel: dont use highest level of optimization on workqueue.c""

This reverts commit 887eede58ee1f6f640313d38aa07e07aaa2b32a5.
Revert "O3 fixes"

This reverts commit 3eed7db4c6ab349d47cfa4d0c24ac16f6cb49e6a.
O3 fixes
Revert "kernel: dont use highest level of optimization on workqueue.c"

This reverts commit aa70951ca8eb512f401381a3ac32008573087d03.
tweaks