This patch removes uses of the Darwin ABI for PowerPC related test cases. This is the first step in removing Darwin support from the POWER backend. clang/test/CodeGen/darwin-ppc-varargs.c was deleted because it was a darwin/ppc specific test case. All other tests were updated to remove the darwin/ppc specific invocation. Phabricator Review: https://reviews.llvm.org/D50989. llvm-svn: 340770