[SPV-IR to OCL] Fix mutated builtin call attribute copying

When SPIRVToOCL20Pass translates following SPV IR
```
  %call = tail call spir_func noundef ptr @_Z42__spirv_GenericCastToPtrExplicit_ToPrivatePvi(ptr addrspace(4) noundef %Ptr, i32 noundef 0)
declare spir_func ptr @_Z42__spirv_GenericCastToPtrExplicit_ToPrivatePvi(ptr addrspace(4), i32)
```
to OCL IR:
```
  %call = tail call spir_func noundef ptr @__to_private(ptr addrspace(4) noundef %Ptr)
declare spir_func ptr @__to_private(ptr addrspace(4))
```
, there is error `Attribute after last parameter` at copying attribute
to the new call because the old call has an additional AttributeSet for
the last argument. The last argument is eliminated.

Set tail call for new call if old call is tail call.

Revert cafd7e0.

Test isn't added since I can only reproduce using SPIRVToOCL20Pass.

lib/SPIRV/SPIRVBuiltinHelper.cpp

@@ -62,8 +62,9 @@ BuiltinCallMutator::BuiltinCallMutator(
     CallInst *CI, std::string FuncName, ManglingRules Rules,
     std::function<std::string(StringRef)> NameMapFn)
     : CI(CI), FuncName(FuncName),
-      Attrs(CI->getCalledFunction()->getAttributes()), ReturnTy(CI->getType()),
-      Args(CI->args()), Rules(Rules), Builder(CI) {
+      Attrs(CI->getCalledFunction()->getAttributes()),
+      CallAttrs(CI->getAttributes()), ReturnTy(CI->getType()), Args(CI->args()),
+      Rules(Rules), Builder(CI) {
   bool DidDemangle = getParameterTypes(CI->getCalledFunction(), PointerTypes,
                                        std::move(NameMapFn));
   if (!DidDemangle) {
@@ -78,8 +79,8 @@ BuiltinCallMutator::BuiltinCallMutator(
 BuiltinCallMutator::BuiltinCallMutator(BuiltinCallMutator &&Other)
     : CI(Other.CI), FuncName(std::move(Other.FuncName)),
       MutateRet(std::move(Other.MutateRet)), Attrs(Other.Attrs),
-      ReturnTy(Other.ReturnTy), Args(std::move(Other.Args)),
-      PointerTypes(std::move(Other.PointerTypes)),
+      CallAttrs(Other.CallAttrs), ReturnTy(Other.ReturnTy),
+      Args(std::move(Other.Args)), PointerTypes(std::move(Other.PointerTypes)),
       Rules(std::move(Other.Rules)), Builder(CI) {
   // Clear the other's CI instance so that it knows not to construct the actual
   // call.
@@ -103,7 +104,8 @@ Value *BuiltinCallMutator::doConversion() {
       Builder.Insert(addCallInst(CI->getModule(), FuncName, ReturnTy, Args,
                                  &Attrs, nullptr, Mangler.get()));
   NewCall->copyMetadata(*CI);
-  NewCall->setAttributes(CI->getAttributes());
+  NewCall->setAttributes(CallAttrs);
+  NewCall->setTailCall(CI->isTailCall());
   Value *Result = MutateRet ? MutateRet(Builder, NewCall) : NewCall;
   Result->takeName(CI);
   if (!CI->getType()->isVoidTy())
@@ -118,6 +120,8 @@ BuiltinCallMutator &BuiltinCallMutator::setArgs(ArrayRef<Value *> NewArgs) {
   // Retain only the function attributes, not any parameter attributes.
   Attrs = AttributeList::get(CI->getContext(), Attrs.getFnAttrs(),
                              Attrs.getRetAttrs(), {});
+  CallAttrs = AttributeList::get(CI->getContext(), CallAttrs.getFnAttrs(),
+                                 CallAttrs.getRetAttrs(), {});
   Args.clear();
   PointerTypes.clear();
   for (Value *Arg : NewArgs) {
@@ -171,6 +175,8 @@ BuiltinCallMutator &BuiltinCallMutator::insertArg(unsigned Index,
   PointerTypes.insert(PointerTypes.begin() + Index, Arg.second);
   moveAttributes(CI->getContext(), Attrs, Index, Args.size() - Index,
                  Index + 1);
+  moveAttributes(CI->getContext(), CallAttrs, Index, Args.size() - Index,
+                 Index + 1);
   return *this;
 }
 
@@ -179,30 +185,21 @@ BuiltinCallMutator &BuiltinCallMutator::replaceArg(unsigned Index,
   Args[Index] = Arg.first;
   PointerTypes[Index] = Arg.second;
   Attrs = Attrs.removeParamAttributes(CI->getContext(), Index);
+  CallAttrs = CallAttrs.removeParamAttributes(CI->getContext(), Index);
   return *this;
 }
 
 BuiltinCallMutator &BuiltinCallMutator::removeArg(unsigned Index) {
   // If the argument being dropped is the last one, there is nothing to move, so
   // just remove the attributes.
+  auto &Ctx = CI->getContext();
   if (Index == Args.size() - 1) {
-    // TODO: Remove this workaround when LLVM fixes
-    // https://github.com/llvm/llvm-project/issues/59746 on
-    // AttributeList::removeParamAttributes function.
-    // AttributeList::removeParamAttributes function sets attribute at
-    // specified index empty so that return value of
-    // AttributeList::getNumAttrSet() keeps unchanged after that call. When call
-    // BuiltinCallMutator::removeArg function, there is assert failure on
-    // BuiltinCallMutator::doConversion() since new CallInst removed arg but
-    // still holds attribute of that removed arg.
-    SmallVector<AttributeSet, 4> ArgAttrs;
-    for (unsigned I = 0; I < Index; ++I)
-      ArgAttrs.push_back(Attrs.getParamAttrs(I));
-    Attrs = AttributeList::get(CI->getContext(), Attrs.getFnAttrs(),
-                               Attrs.getRetAttrs(), ArgAttrs);
-  } else
-    moveAttributes(CI->getContext(), Attrs, Index + 1, Args.size() - Index - 1,
-                   Index);
+    Attrs = Attrs.removeParamAttributes(Ctx, Index);
+    CallAttrs = CallAttrs.removeParamAttributes(Ctx, Index);
+  } else {
+    moveAttributes(Ctx, Attrs, Index + 1, Args.size() - Index - 1, Index);
+    moveAttributes(Ctx, CallAttrs, Index + 1, Args.size() - Index - 1, Index);
+  }
   Args.erase(Args.begin() + Index);
   PointerTypes.erase(PointerTypes.begin() + Index);
   return *this;

lib/SPIRV/SPIRVBuiltinHelper.h

@@ -74,8 +74,10 @@ class BuiltinCallMutator {
   // the new instruction is created.
   std::function<llvm::Value *(llvm::IRBuilder<> &, llvm::CallInst *)> MutateRet;
   typedef decltype(MutateRet) MutateRetFuncTy;
-  // The attribute list for the new call instruction.
+  // The attribute list for the new called function.
   llvm::AttributeList Attrs;
+  // The attribute list for the new call instruction.
+  llvm::AttributeList CallAttrs;
   // The return type for the new call instruction.
   llvm::Type *ReturnTy;
   // The arguments for the new call instruction.