revert r177211 due to its potential issues

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177222 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCXXABI.h b/lib/CodeGen/CGCXXABI.h
index d0384ec..cdc87b7 100644
--- a/lib/CodeGen/CGCXXABI.h
+++ b/lib/CodeGen/CGCXXABI.h
@@ -91,10 +91,6 @@
     return *MangleCtx;
   }
 
-  /// Returns true if the given instance method is one of the
-  /// kinds that the ABI says returns 'this'.
-  virtual bool HasThisReturn(GlobalDecl GD) const { return false; }
-
   /// Find the LLVM type used to represent the given member pointer
   /// type.
   virtual llvm::Type *
@@ -213,8 +209,7 @@
   /// Emit the ABI-specific prolog for the function.
   virtual void EmitInstanceFunctionProlog(CodeGenFunction &CGF) = 0;
 
-  /// Emit the constructor call. Return the function that is called.
-  virtual llvm::Value *EmitConstructorCall(CodeGenFunction &CGF,
+  virtual void EmitConstructorCall(CodeGenFunction &CGF,
                                    const CXXConstructorDecl *D,
                                    CXXCtorType Type, bool ForVirtualBase,
                                    bool Delegating,