Compute feature bits at time of MCSubtargetInfo initialization.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134606 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCSubtarget.h b/lib/Target/PowerPC/PPCSubtarget.h
index c89f922..e028de6 100644
--- a/lib/Target/PowerPC/PPCSubtarget.h
+++ b/lib/Target/PowerPC/PPCSubtarget.h
@@ -26,6 +26,7 @@
 #undef PPC
 
 namespace llvm {
+class StringRef;
 
 namespace PPC {
   // -m directive values.
@@ -80,8 +81,7 @@
   
   /// ParseSubtargetFeatures - Parses features string setting specified 
   /// subtarget options.  Definition of function is auto generated by tblgen.
-  void ParseSubtargetFeatures(const std::string &FS, const std::string &CPU);
-
+  void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
   
   /// SetJITMode - This is called to inform the subtarget info that we are
   /// producing code for the JIT.