Begin the migration of header search logic to the driver, starting with
Windows. There are still FIXMEs and lots of problems with this code.
Some of them will be addressed shortly by my follow-up patches, but most
are going to wait until we isolate this code and can fix it properly.
This version should be no worse than what we had before.

llvm-svn: 143752
diff --git a/clang/lib/Driver/ToolChains.h b/clang/lib/Driver/ToolChains.h
index dfcb253..f0c3484 100644
--- a/clang/lib/Driver/ToolChains.h
+++ b/clang/lib/Driver/ToolChains.h
@@ -417,6 +417,12 @@
   virtual bool IsUnwindTablesDefault() const;
   virtual const char *GetDefaultRelocationModel() const;
   virtual const char *GetForcedPicModel() const;
+
+  virtual void AddClangSystemIncludeArgs(const ArgList &DriverArgs,
+                                         ArgStringList &CC1Args) const;
+  virtual void AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
+                                            ArgStringList &CC1Args) const;
+
 };
 
 } // end namespace toolchains