4.14 patches for arm32 clang

Greg, Please see the attached mbox of 5 patches. The first required a slight backport as noted in the commit message, but the others applied cleanly. Here's a build+boot of them in clang: https://travis-ci.com/ClangBuiltLinux/continuous-integration/builds/92778054 (obviously we need to backport warning cleanups, but this set gets it booting at least)