On non-apple systems, when using -march=ppc32, do not print:

'' is not a recognized processor for this target (ignoring processor)

Default to "generic" instead of "" for the default CPU.

llvm-svn: 23257
diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
index 3196f09..62f36c6 100644
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
@@ -123,7 +123,7 @@
   : StackAlignment(16), IsGigaProcessor(false), IsAIX(false), IsDarwin(false) {
 
   // Determine default and user specified characteristics
-  std::string CPU;
+  std::string CPU = "generic";
 #if defined(__APPLE__)
   CPU = GetCurrentPowerPCCPU();
 #endif