[ELF] Use llvm::bsearch. NFC

[ruiu]

LGTM

Nice

ELF/DWARF.cpp

85

We usually just use = or & to capture variables.

ELF/InputSection.cpp

1228

Ditto

[MaskRay]

Use = to capture variables.

ELF/DWARF.cpp

 // Find if there is a relocation at Pos in Sec.  The code is a bit
 // more complicated than usual because we need to pass a section index
 // to llvm since it has no idea about InputSection.
 template <class ELFT>
 template <class RelTy>
 Optional<RelocAddrEntry>
 LLDDwarfObj<ELFT>::findAux(const InputSectionBase &Sec, uint64_t Pos,
                            ArrayRef<RelTy> Rels) const {
-  auto It = std::lower_bound(
-      Rels.begin(), Rels.end(), Pos,
-      [](const RelTy &A, uint64_t B) { return A.r_offset < B; });
+  auto It =
+      llvm::bsearch(Rels, [=](const RelTy &A) { return Pos <= A.r_offset; });
   if (It == Rels.end() || It->r_offset != Pos)
     return None;
   const RelTy &Rel = *It;
 
   const ObjFile<ELFT> *File = Sec.getFile<ELFT>();
   uint32_t SymIndex = Rel.getSymbol(Config->IsMips64EL);
   const typename ELFT::Sym &Sym = File->template getELFSyms<ELFT>()[SymIndex];
   uint32_t SecIndex = File->getSectionIndex(Sym);

ELF/InputSection.cpp

 }
 
 SectionPiece *MergeInputSection::getSectionPiece(uint64_t Offset) {
   if (this->data().size() <= Offset)
     fatal(toString(this) + ": offset is outside the section");
 
   // If Offset is not at beginning of a section piece, it is not in the map.
   // In that case we need to  do a binary search of the original section piece vector.
-  auto It2 =
-      llvm::upper_bound(Pieces, Offset, [](uint64_t Offset, SectionPiece P) {
-        return Offset < P.InputOff;
-      });
-  return &It2[-1];
+  auto It = llvm::bsearch(Pieces,
+                          [=](SectionPiece P) { return Offset < P.InputOff; });
+  return &It[-1];
 }
 
 // Returns the offset in an output section for a given input offset.
 // Because contents of a mergeable section is not contiguous in output,
 // it is not just an addition to a base output offset.
 uint64_t MergeInputSection::getParentOffset(uint64_t Offset) const {
   // If Offset is not at beginning of a section piece, it is not in the map.
   // In that case we need to search from the original section piece vector.