Revert "revert r179735, it has no testcases, and doesn't really make sense."

This un-reverts r179735 and reverts commit r180574.

This fixes assertion failures for me locally and should fix the failures
on Windows reported widely on llvm-dev.  We should check if the bots
caught this and if so why not.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180722 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/IR/AttributeImpl.h b/lib/IR/AttributeImpl.h
index 8e9c30d..b17aa43 100644
--- a/lib/IR/AttributeImpl.h
+++ b/lib/IR/AttributeImpl.h
@@ -178,7 +178,7 @@
 
   unsigned getAlignment() const;
   unsigned getStackAlignment() const;
-  std::string getAsString(bool InAttrGrp) const;
+  std::string getAsString(bool TargetIndependent, bool InAttrGrp) const;
 
   typedef SmallVectorImpl<Attribute>::iterator       iterator;
   typedef SmallVectorImpl<Attribute>::const_iterator const_iterator;