Fix wrong frame pointer save offset in the 64-bit PowerPC SVR4 ABI.

Patch contributed by Ken Werner of IBM!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91681 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCFrameInfo.h b/lib/Target/PowerPC/PPCFrameInfo.h
index 73d30bf..7587b03 100644
--- a/lib/Target/PowerPC/PPCFrameInfo.h
+++ b/lib/Target/PowerPC/PPCFrameInfo.h
@@ -50,7 +50,7 @@
       return isPPC64 ? -8U : -4U;
     
     // SVR4 ABI: First slot in the general register save area.
-    return -4U;
+    return isPPC64 ? -8U : -4U;
   }
   
   /// getLinkageSize - Return the size of the PowerPC ABI linkage area.