[WebAssembly] Don't make wasm cleanuppads into funclet entries

[aheejin]

Summary

Catchpads and cleanuppads are not funclet entries; they are only EH
scope entries. We already dont't set isEHFuncletEntry for catchpads.
This patch does the same thing for cleanuppads.

[aheejin]

Remove a TODO line

[aheejin]

rebase

lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

SDValue Ret = DAG.getNode(ISD::CATCHRET, getCurSDLoc(), MVT::Other,
                             DAG.getBasicBlock(SuccessorColorMBB));
   DAG.setRoot(Ret);
 }
 
 void SelectionDAGBuilder::visitCleanupPad(const CleanupPadInst &CPI) {
   // Don't emit any special code for the cleanuppad instruction. It just marks
   // the start of an EH scope/funclet.
   FuncInfo.MBB->setIsEHScopeEntry();
+  auto Pers = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn());
+  if (Pers != EHPersonality::Wasm_CXX) {
     FuncInfo.MBB->setIsEHFuncletEntry();
     FuncInfo.MBB->setIsCleanupFuncletEntry();
   }
+}
 
 /// When an invoke or a cleanupret unwinds to the next EH pad, there are
 /// many places it could ultimately go. In the IR, we have a single unwind
 /// destination, but in the machine CFG, we enumerate all the possible blocks.
 /// This function skips over imaginary basic blocks that hold catchswitch
 /// instructions, and finds all the "real" machine
 /// basic block destinations. As those destinations may not be successors of
 /// EHPadBB, here we also calculate the edge probability to those destinations.
 /// The passed-in Prob is the edge probability to EHPadBB.
 static void findUnwindDestinations(
     FunctionLoweringInfo &FuncInfo, const BasicBlock *EHPadBB,
     BranchProbability Prob,
     SmallVectorImpl<std::pair<MachineBasicBlock *, BranchProbability>>
         &UnwindDests) {
   EHPersonality Personality =
     classifyEHPersonality(FuncInfo.Fn->getPersonalityFn());
   bool IsMSVCCXX = Personality == EHPersonality::MSVC_CXX;
   bool IsCoreCLR = Personality == EHPersonality::CoreCLR;
+  bool IsWasmCXX = Personality == EHPersonality::Wasm_CXX;
   bool IsSEH = isAsynchronousEHPersonality(Personality);
 
   while (EHPadBB) {
     const Instruction *Pad = EHPadBB->getFirstNonPHI();
     BasicBlock *NewEHPadBB = nullptr;
     if (isa<LandingPadInst>(Pad)) {
       // Stop on landingpads. They are not funclets.
       UnwindDests.emplace_back(FuncInfo.MBBMap[EHPadBB], Prob);
       break;
     } else if (isa<CleanupPadInst>(Pad)) {
       // Stop on cleanup pads. Cleanups are always funclet entries for all known
       // personalities.
       UnwindDests.emplace_back(FuncInfo.MBBMap[EHPadBB], Prob);
       UnwindDests.back().first->setIsEHScopeEntry();
+      if (!IsWasmCXX)
         UnwindDests.back().first->setIsEHFuncletEntry();
       break;
     } else if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(Pad)) {
       // Add the catchpad handlers to the possible destinations.
       for (const BasicBlock *CatchPadBB : CatchSwitch->handlers()) {
         UnwindDests.emplace_back(FuncInfo.MBBMap[CatchPadBB], Prob);
         // For MSVC++ and the CLR, catchblocks are funclets and need prologues.
         if (IsMSVCCXX || IsCoreCLR)
           UnwindDests.back().first->setIsEHFuncletEntry();

test/CodeGen/WebAssembly/exception.ll

 ; CHECK-LABEL: test_no_prolog_epilog_in_ehpad
 ; CHECK:  try
 ; CHECK:  call      foo@FUNCTION
 ; CHECK:  i32.catch
 ; CHECK-NOT:  get_global  $push{{.+}}=, __stack_pointer@GLOBAL
 ; CHECK:  try
 ; CHECK:  call      foo@FUNCTION
 ; CHECK:  catch_all
-; TODO This should be removed too in a later patch
-; CHECK-NO T:  get_global  $push{{.+}}=, __stack_pointer@GLOBAL
+; CHECK-NOT:  get_global  $push{{.+}}=, __stack_pointer@GLOBAL
 ; CHECK:  call      __cxa_end_catch@FUNCTION
 ; CHECK-NOT:  set_global  __stack_pointer@GLOBAL, $pop{{.+}}
 ; CHECK:  end_try
 ; CHECK-NOT:  set_global  __stack_pointer@GLOBAL, $pop{{.+}}
 ; CHECK:  end_try
 define void @test_no_prolog_epilog_in_ehpad() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
 entry:
   %stack_var = alloca i32, align 4