[BOLT][NFC] Suppress unused variable warnings

[Amir]

Summary

Addresses the warnings emitted by Apple Clang 13.1.6 (Xcode 13.3.1).
Tip @tschuett issue #55404.

[rafauler]

LGTM

bolt/lib/Core/BinaryBasicBlock.cpp

if (*PredI == Pred) {
       PredI = Predecessors.erase(PredI);
       if (!Multiple)
         return;
     } else {
       ++PredI;
     }
   }
   assert(Erased && "Pred is not a predecessor of this block!");
+  (void)Erased;
 }
 
 void BinaryBasicBlock::removeDuplicateConditionalSuccessor(MCInst *CondBranch) {
   assert(succ_size() == 2 && Successors[0] == Successors[1] &&
          "conditional successors expected");
 
   BinaryBasicBlock *Succ = Successors[0];
   const BinaryBranchInfo CondBI = BranchInfo[0];

bolt/lib/Core/BinaryContext.cpp

BinaryContext::duplicateJumpTable(BinaryFunction &Function, JumpTable *JT,
   for (std::pair<const unsigned, MCSymbol *> Elmt : JT->Labels) {
     if (Elmt.second != OldLabel)
       continue;
     Offset = Elmt.first;
     Found = true;
     break;
   }
   assert(Found && "Label not found");
+  (void)Found;
   MCSymbol *NewLabel = Ctx->createNamedTempSymbol("duplicatedJT");
   JumpTable *NewJT =
       new JumpTable(*NewLabel, JT->getAddress(), JT->EntrySize, JT->Type,
                     JumpTable::LabelMapType{{Offset, NewLabel}}, Function,
                     *getSectionForAddress(JT->getAddress()));
   NewJT->Entries = JT->Entries;
   NewJT->Counts = JT->Counts;
   uint64_t JumpTableID = ++DuplicatedJumpTables;
if ((BD->getName().startswith("SYMBOLat") ||
          BD->getName().startswith("DATAat")) &&
         !BD->getParent() && !BD->getSize() && !BD->isAbsolute() &&
         BD->getSection()) {
       errs() << "BOLT-WARNING: zero-sized top level symbol: " << *BD << "\n";
       Valid = false;
     }
   }
   assert(Valid);
+  (void)Valid;
   generateSymbolHashes();
 }
 
 void BinaryContext::foldFunction(BinaryFunction &ChildBF,
                                  BinaryFunction &ParentBF) {
   assert(!ChildBF.isMultiEntry() && !ParentBF.isMultiEntry() &&
          "cannot merge functions with multiple entry points");
 

bolt/lib/Rewrite/RewriteInstance.cpp

for (const ELF64LE::Shdr &Section : cantFail(Obj.sections())) {
 
     // Perform section post-processing.
     if (BSec && !BSec->isAllocatable()) {
       assert(BSec->getAlignment() <= Section.sh_addralign &&
              "alignment exceeds value in file");
 
       if (BSec->getAllocAddress()) {
         assert(!DataWritten && "Writing section twice.");
+        (void)DataWritten;
         SectionData = BSec->getOutputData();
 
         LLVM_DEBUG(dbgs() << "BOLT-DEBUG: " << (Size ? "appending" : "writing")
                           << " contents to section " << SectionName << '\n');
         OS.write(reinterpret_cast<char *>(SectionData), BSec->getOutputSize());
         Size += BSec->getOutputSize();
       }