Revert "[PowerPC] Improve consistency in use of __ppc__, __powerpc__, etc."

This reverts commit r187248. It broke many bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187254 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/ADT/PackedVectorTest.cpp b/unittests/ADT/PackedVectorTest.cpp
index b6a7e58..55b5d8d 100644
--- a/unittests/ADT/PackedVectorTest.cpp
+++ b/unittests/ADT/PackedVectorTest.cpp
@@ -9,7 +9,7 @@
 
 // BitVectorTest tests fail on PowerPC for unknown reasons, so disable this
 // as well since it depends on a BitVector.
-#if !defined(__ppc__) && !defined(__powerpc__)
+#ifndef __ppc__
 
 #include "llvm/ADT/PackedVector.h"
 #include "gtest/gtest.h"