Redirect pointerSize query to the TargetMachine in ASMPrinter

Summary:
Because llvm-dsymutil is using ASMPrinter without any MachineFunction
of Module available.

This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D11078

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242384 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/AsmPrinter/AsmPrinter.cpp

@@ -140,6 +140,8 @@ const DataLayout &AsmPrinter::getDataLayout() const {
   return *TM.getDataLayout();
 }
 
+unsigned AsmPrinter::getPointerSize() const { return TM.getDataLayout()->getPointerSize(); }
+
 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
   assert(MF && "getSubtargetInfo requires a valid MachineFunction!");
   return MF->getSubtarget<MCSubtargetInfo>();