Now Attributes are divided in three groups

- return attributes - inreg, zext and sext
- parameter attributes
- function attributes - nounwind, readonly, readnone, noreturn

Return attributes use 0 as the index.
Function attributes use ~0U as the index.

llvm-svn: 56705

clang/lib/CodeGen/CodeGenModule.cpp

@@ -240,7 +240,7 @@ void CodeGenModule::SetFunctionAttributesForDefinition(const Decl *D,
   }
                              
   if (!Features.Exceptions)
-    F->addAttribute(0, llvm::Attribute::NoUnwind);  
+    F->addAttribute(~0, llvm::Attribute::NoUnwind);  
 }
 
 void CodeGenModule::SetMethodAttributes(const ObjCMethodDecl *MD,