Use const qualifiers with TargetLowering. This eliminates several
const_casts, and it reinforces the design of the Target classes being
immutable.

SelectionDAGISel::IsLegalToFold is now a static member function, because
PIC16 uses it in an unconventional way. There is more room for API
cleanup here.

And PIC16's AsmPrinter no longer uses TargetLowering.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101635 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp b/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
index 04538d1..7b328bb 100644
--- a/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
+++ b/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "MSP430.h"
-#include "MSP430ISelLowering.h"
 #include "MSP430TargetMachine.h"
 #include "llvm/DerivedTypes.h"
 #include "llvm/Function.h"
@@ -100,7 +99,7 @@
 ///
 namespace {
   class MSP430DAGToDAGISel : public SelectionDAGISel {
-    MSP430TargetLowering &Lowering;
+    const MSP430TargetLowering &Lowering;
     const MSP430Subtarget &Subtarget;
 
   public:
@@ -364,7 +363,7 @@
                                                unsigned Opc8, unsigned Opc16) {
   if (N1.getOpcode() == ISD::LOAD &&
       N1.hasOneUse() &&
-      IsLegalToFold(N1, Op, Op)) {
+      IsLegalToFold(N1, Op, Op, OptLevel)) {
     LoadSDNode *LD = cast<LoadSDNode>(N1);
     if (!isValidIndexedLoad(LD))
       return NULL;