[MC] [Win64EH] Remove an unused parameter to ARM64EmitUnwindCode. NFC.

[zzheng]

LGTM.

llvm/lib/MC/MCWin64EH.cpp

case Win64EH::UOP_ClearUnwoundToCall:
       break;
     }
   }
   return Count;
 }
 
 // Unwind opcode encodings and restrictions are documented at
 // https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling
-static void ARM64EmitUnwindCode(MCStreamer &streamer, const MCSymbol *begin,
+static void ARM64EmitUnwindCode(MCStreamer &streamer,
                                 const WinEH::Instruction &inst) {
   uint8_t b, reg;
   switch (static_cast<Win64EH::UnwindOpcodes>(inst.Operation)) {
   default:
     llvm_unreachable("Unsupported ARM64 unwind code");
   case Win64EH::UOP_AllocSmall:
     b = (inst.Offset >> 4) & 0x1F;
     streamer.emitInt8(b);
if (PackedEpilogOffset < 0) {
     }
   }
 
   // Emit prolog unwind instructions (in reverse order).
   uint8_t numInst = info->Instructions.size();
   for (uint8_t c = 0; c < numInst; ++c) {
     WinEH::Instruction inst = info->Instructions.back();
     info->Instructions.pop_back();
-    ARM64EmitUnwindCode(streamer, info->Begin, inst);
+    ARM64EmitUnwindCode(streamer, inst);
   }
 
   // Emit epilog unwind instructions
   for (auto &I : info->EpilogMap) {
     auto &EpilogInstrs = I.second;
     for (const WinEH::Instruction &inst : EpilogInstrs)
-      ARM64EmitUnwindCode(streamer, info->Begin, inst);
+      ARM64EmitUnwindCode(streamer, inst);
   }
 
   int32_t BytesMod = CodeWords * 4 - TotalCodeBytes;
   assert(BytesMod >= 0);
   for (int i = 0; i < BytesMod; i++)
     streamer.emitInt8(0xE3);
 
   if (info->HandlesExceptions)