GlobalISel: Add CallBase to CallLoweringInfo

[arsenm]

Summary

The DAG version has this, and is necessary for call lowering to take
advantage of any attributes at the call site.

[paquette]

LGTM

[arsenm]

3fdcd9bb1371990399aeadb9aef1df9d74598a83

llvm/include/llvm/CodeGen/GlobalISel/CallLowering.h

struct CallLoweringInfo {
 
     /// List of descriptors of the arguments passed to the function.
     SmallVector<ArgInfo, 32> OrigArgs;
 
     /// Valid if the call has a swifterror inout parameter, and contains the
     /// vreg that the swifterror should be copied into after the call.
     Register SwiftErrorVReg;
 
+    /// Original IR callsite corresponding to this call, if available.
+    const CallBase *CB = nullptr;
+
     MDNode *KnownCallees = nullptr;
 
     /// True if the call must be tail call optimized.
     bool IsMustTailCall = false;
 
     /// True if the call passes all target-independent checks for tail call
     /// optimization.
     bool IsTailCall = false;

llvm/lib/CodeGen/GlobalISel/CallLowering.cpp

if (const Function *F = dyn_cast<Function>(CalleeV))
     Info.Callee = MachineOperand::CreateGA(F, 0);
   else
     Info.Callee = MachineOperand::CreateReg(GetCalleeReg(), false);
 
   Info.OrigRet = ArgInfo{ResRegs, RetTy, 0, ISD::ArgFlagsTy{}};
   if (!Info.OrigRet.Ty->isVoidTy())
     setArgFlags(Info.OrigRet, AttributeList::ReturnIndex, DL, CB);
 
+  Info.CB = &CB;
   Info.KnownCallees = CB.getMetadata(LLVMContext::MD_callees);
   Info.CallConv = CallConv;
   Info.SwiftErrorVReg = SwiftErrorVReg;
   Info.IsMustTailCall = CB.isMustTailCall();
   Info.IsTailCall = CanBeTailCalled;
   Info.IsVarArg = IsVarArg;
   return lowerCall(MIRBuilder, Info);
 }