Revert commit from upstream llvm trunk (by Hans Wennborg):
Re-commit r357452 (take 3): "SimplifyCFG SinkCommonCodeFromPredecessors: Also sink function calls without used results (PR41259)" Third time's the charm. This was reverted in r363220 due to being suspected of an internal benchmark regression and a test failure, none of which turned out to be caused by this.
As reported in https://bugs.llvm.org/show_bug.cgi?id=43269, this causes
UNREACHABLE errors when compiling if_malo_pci.c for arm and aarch64.