ppc patch queue 2018-01-21 This request supersedes the one from 2018-01-19. The only difference is that the patch deprecating ppcemb-softmmu, and thereby creating many annying warnings from make check has been removed. Highlights are: * Significant TCG speedup by optimizing cmp generation * Fix a regression caused by recent change to set compat mode on hotplugged cpus * Cleanup of default configs * Some implementation of msgsnd/msgrcv instructions for server chips