[ELF] Optimize two vector. NFC

lld/ELF/MapFile.cpp

@@ -91,9 +91,9 @@ static SymbolMapTy getSectionSyms(ArrayRef<Defined *> syms) {
 // we do that in batch using parallel-for.
 static DenseMap<Symbol *, std::string>
 getSymbolStrings(ArrayRef<Defined *> syms) {
-  std::vector<std::string> str(syms.size());
+  auto strs = std::make_unique<std::string[]>(syms.size());
   parallelForEachN(0, syms.size(), [&](size_t i) {
-    raw_string_ostream os(str[i]);
+    raw_string_ostream os(strs[i]);
     OutputSection *osec = syms[i]->getOutputSection();
     uint64_t vma = syms[i]->getVA();
     uint64_t lma = osec ? osec->getLMA() + vma - osec->getVA(0) : 0;
@@ -103,7 +103,7 @@ getSymbolStrings(ArrayRef<Defined *> syms) {
 
   DenseMap<Symbol *, std::string> ret;
   for (size_t i = 0, e = syms.size(); i < e; ++i)
-    ret[syms[i]] = std::move(str[i]);
+    ret[syms[i]] = std::move(strs[i]);
   return ret;
 }
 

lld/ELF/Writer.cpp

@@ -1750,16 +1750,15 @@ template <class ELFT> void Writer<ELFT>::optimizeBasicBlockJumps() {
     if (!(osec->flags & SHF_EXECINSTR))
       continue;
     SmallVector<InputSection *, 0> sections = getInputSections(*osec);
-    std::vector<unsigned> result(sections.size());
+    size_t numDeleted = 0;
     // Delete all fall through jump instructions.  Also, check if two
     // consecutive jump instructions can be flipped so that a fall
     // through jmp instruction can be deleted.
     for (size_t i = 0, e = sections.size(); i != e; ++i) {
       InputSection *next = i + 1 < sections.size() ? sections[i + 1] : nullptr;
       InputSection &sec = *sections[i];
-      result[i] = target->deleteFallThruJmpInsn(sec, sec.file, next) ? 1 : 0;
+      numDeleted += target->deleteFallThruJmpInsn(sec, sec.file, next);
     }
-    size_t numDeleted = std::count(result.begin(), result.end(), 1);
     if (numDeleted > 0) {
       script->assignAddresses();
       LLVM_DEBUG(llvm::dbgs()