Improve MachineMemOperand handling.

- Allocate MachineMemOperands and MachineMemOperand lists in MachineFunctions.
   This eliminates MachineInstr's std::list member and allows the data to be
   created by isel and live for the remainder of codegen, avoiding a lot of
   copying and unnecessary translation. This also shrinks MemSDNode.
 - Delete MemOperandSDNode. Introduce MachineSDNode which has dedicated
   fields for MachineMemOperands.
 - Change MemSDNode to have a MachineMemOperand member instead of its own
   fields with the same information. This introduces some redundancy, but
   it's more consistent with what MachineInstr will eventually want.
 - Ignore alignment when searching for redundant loads for CSE, but remember
   the greatest alignment.

Target-specific code which previously used MemOperandSDNodes with generic
SDNodes now use MemIntrinsicSDNodes, with opcodes in a designated range
so that the SelectionDAG framework knows that MachineMemOperand information
is available.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82794 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/ScheduleDAGEmit.cpp

@@ -28,10 +28,6 @@
 #include "llvm/Support/MathExtras.h"
 using namespace llvm;
 
-void ScheduleDAG::AddMemOperand(MachineInstr *MI, const MachineMemOperand &MO) {
-  MI->addMemOperand(MF, MO);
-}
-
 void ScheduleDAG::EmitNoop() {
   TII->insertNoop(*BB, InsertPos);
 }