[WebAssembly] Method order change in LateEHPrepare (NFC)

[aheejin]

Summary

Currently the order of these methods does not matter, but the following
CL needs to have this order changed. Merging the order change and the
semantics change within a CL complicates the diff, so submitting the
order change first.

[aheejin]

More order change

lib/Target/WebAssembly/WebAssemblyLateEHPrepare.cpp

 namespace {
 class WebAssemblyLateEHPrepare final : public MachineFunctionPass {
   StringRef getPassName() const override {
     return "WebAssembly Late Prepare Exception";
   }
 
   bool runOnMachineFunction(MachineFunction &MF) override;
   bool removeUnnecessaryUnreachables(MachineFunction &MF);
-  bool replaceFuncletReturns(MachineFunction &MF);
   bool addCatches(MachineFunction &MF);
+  bool replaceFuncletReturns(MachineFunction &MF);
   bool addExceptionExtraction(MachineFunction &MF);
   bool restoreStackPointer(MachineFunction &MF);
 
 public:
   static char ID; // Pass identification, replacement for typeid
   WebAssemblyLateEHPrepare() : MachineFunctionPass(ID) {}
 };
 } // end anonymous namespace
bool WebAssemblyLateEHPrepare::runOnMachineFunction(MachineFunction &MF) {
   if (MF.getTarget().getMCAsmInfo()->getExceptionHandlingType() !=
       ExceptionHandling::Wasm)
     return false;
 
   bool Changed = false;
   Changed |= removeUnnecessaryUnreachables(MF);
   if (!MF.getFunction().hasPersonalityFn())
     return Changed;
-  Changed |= replaceFuncletReturns(MF);
   Changed |= addCatches(MF);
+  Changed |= replaceFuncletReturns(MF);
   Changed |= addExceptionExtraction(MF);
   Changed |= restoreStackPointer(MF);
   return Changed;
 }
 
 bool WebAssemblyLateEHPrepare::removeUnnecessaryUnreachables(
     MachineFunction &MF) {
   bool Changed = false;
for (auto &MI : MBB) {
         MBB.removeSuccessor(Succ);
       eraseDeadBBsAndChildren(Succs);
     }
   }
 
   return Changed;
 }
 
+// Add catch instruction to beginning of catchpads and cleanuppads.
+bool WebAssemblyLateEHPrepare::addCatches(MachineFunction &MF) {
+  bool Changed = false;
+  const auto &TII = *MF.getSubtarget<WebAssemblySubtarget>().getInstrInfo();
+  MachineRegisterInfo &MRI = MF.getRegInfo();
+  for (auto &MBB : MF) {
+    if (MBB.isEHPad()) {
+      Changed = true;
+      auto InsertPos = MBB.begin();
+      if (InsertPos->isEHLabel()) // EH pad starts with an EH label
+        ++InsertPos;
+      unsigned DstReg =
+          MRI.createVirtualRegister(&WebAssembly::EXCEPT_REFRegClass);
+      BuildMI(MBB, InsertPos, MBB.begin()->getDebugLoc(),
+              TII.get(WebAssembly::CATCH), DstReg);
+    }
+  }
+  return Changed;
+}
+
 bool WebAssemblyLateEHPrepare::replaceFuncletReturns(MachineFunction &MF) {
   bool Changed = false;
   const auto &TII = *MF.getSubtarget<WebAssemblySubtarget>().getInstrInfo();
 
   for (auto &MBB : MF) {
     auto Pos = MBB.getFirstTerminator();
     if (Pos == MBB.end())
       continue;
case WebAssembly::CLEANUPRET: {
       Changed = true;
       break;
     }
     }
   }
   return Changed;
 }
 
-// Add catch instruction to beginning of catchpads and cleanuppads.
-bool WebAssemblyLateEHPrepare::addCatches(MachineFunction &MF) {
-  bool Changed = false;
-  const auto &TII = *MF.getSubtarget<WebAssemblySubtarget>().getInstrInfo();
-  MachineRegisterInfo &MRI = MF.getRegInfo();
-  for (auto &MBB : MF) {
-    if (MBB.isEHPad()) {
-      Changed = true;
-      auto InsertPos = MBB.begin();
-      if (InsertPos->isEHLabel()) // EH pad starts with an EH label
-        ++InsertPos;
-      unsigned DstReg =
-          MRI.createVirtualRegister(&WebAssembly::EXCEPT_REFRegClass);
-      BuildMI(MBB, InsertPos, MBB.begin()->getDebugLoc(),
-              TII.get(WebAssembly::CATCH), DstReg);
-    }
-  }
-  return Changed;
-}
-
 // Wasm uses 'br_on_exn' instruction to check the tag of an exception. It takes
 // except_ref type object returned by 'catch', and branches to the destination
 // if it matches a given tag. We currently use __cpp_exception symbol to
 // represent the tag for all C++ exceptions.
 //
 // block $l (result i32)
 //   ...
 //   ;; except_ref $e is on the stack at this point