The binutils for the IBM BG/P are too old to support CFI.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153886 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCSubtarget.h b/lib/Target/PowerPC/PPCSubtarget.h
index fbd97de..a275029 100644
--- a/lib/Target/PowerPC/PPCSubtarget.h
+++ b/lib/Target/PowerPC/PPCSubtarget.h
@@ -145,6 +145,8 @@
 
   /// isDarwin - True if this is any darwin platform.
   bool isDarwin() const { return TargetTriple.isMacOSX(); }
+  /// isBGP - True if this is a BG/P platform.
+  bool isBGP() const { return TargetTriple.getVendor() == Triple::BGP; }
 
   bool isDarwinABI() const { return isDarwin(); }
   bool isSVR4ABI() const { return !isDarwin(); }