Remove the ASTContext parameter from the attribute-related methods of Decl.

The implementations of these methods can Use Decl::getASTContext() to get the ASTContext.

This commit touches a lot of files since call sites for these methods are everywhere.
I used pre-tokenized "carbon.h" and "cocoa.h" headers to do some timings, and there was no real time difference between before the commit and after it.

llvm-svn: 74501

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -199,7 +199,7 @@ void CodeGenFunction::StartFunction(const Decl *D, QualType RetTy,
 void CodeGenFunction::GenerateCode(const FunctionDecl *FD,
                                    llvm::Function *Fn) {
   // Check if we should generate debug info for this function.
-  if (CGM.getDebugInfo() && !FD->hasAttr<NodebugAttr>(getContext()))
+  if (CGM.getDebugInfo() && !FD->hasAttr<NodebugAttr>())
     DebugInfo = CGM.getDebugInfo();
   
   FunctionArgList Args;