revert r340135: [CodeGen] add rotate builtins

At least a couple of bots (PPC only?) are showing the compiler dying while trying to compile:
http://lab.llvm.org:8011/builders/clang-ppc64be-linux-multistage/builds/11065/steps/build%20stage%201/logs/stdio
http://lab.llvm.org:8011/builders/clang-ppc64be-linux-lnt/builds/18267/steps/build%20stage%201/logs/stdio

llvm-svn: 340136