[BOLT] Remove unsupported ELF format reloc handling

[urnathan]

Summary

RewriteInstance's reloc handling uses dyncast to select between the 4 ELF formats. But everywhere else RewriteInstance only handles LE64 ELF, so this dyncasting is unnecessary. Just cast to the expected ELF type and be done with it.

[rafauler]

LGTM

bolt/lib/Rewrite/RewriteInstance.cpp

int64_t getRelocationAddend(const ELFObjectFile<ELFT> *Obj,
   }
   }
 
   return Addend;
 }
 
 int64_t getRelocationAddend(const ELFObjectFileBase *Obj,
                             const RelocationRef &Rel) {
-  if (auto *ELF32LE = dyn_cast<ELF32LEObjectFile>(Obj))
-    return getRelocationAddend(ELF32LE, Rel);
-  if (auto *ELF64LE = dyn_cast<ELF64LEObjectFile>(Obj))
-    return getRelocationAddend(ELF64LE, Rel);
-  if (auto *ELF32BE = dyn_cast<ELF32BEObjectFile>(Obj))
-    return getRelocationAddend(ELF32BE, Rel);
-  auto *ELF64BE = cast<ELF64BEObjectFile>(Obj);
-  return getRelocationAddend(ELF64BE, Rel);
+  return getRelocationAddend(cast<ELF64LEObjectFile>(Obj), Rel);
 }
 
 template <typename ELFT>
 uint32_t getRelocationSymbol(const ELFObjectFile<ELFT> *Obj,
                              const RelocationRef &RelRef) {
   using ELFShdrTy = typename ELFT::Shdr;
   uint32_t Symbol = 0;
   const ELFFile<ELFT> &EF = Obj->getELFFile();
case ELF::SHT_RELA:
     break;
   }
 
   return Symbol;
 }
 
 uint32_t getRelocationSymbol(const ELFObjectFileBase *Obj,
                              const RelocationRef &Rel) {
-  if (auto *ELF32LE = dyn_cast<ELF32LEObjectFile>(Obj))
-    return getRelocationSymbol(ELF32LE, Rel);
-  if (auto *ELF64LE = dyn_cast<ELF64LEObjectFile>(Obj))
-    return getRelocationSymbol(ELF64LE, Rel);
-  if (auto *ELF32BE = dyn_cast<ELF32BEObjectFile>(Obj))
-    return getRelocationSymbol(ELF32BE, Rel);
-  auto *ELF64BE = cast<ELF64BEObjectFile>(Obj);
-  return getRelocationSymbol(ELF64BE, Rel);
+  return getRelocationSymbol(cast<ELF64LEObjectFile>(Obj), Rel);
 }
 } // anonymous namespace
 
 bool RewriteInstance::analyzeRelocation(
     const RelocationRef &Rel, uint64_t &RType, std::string &SymbolName,
     bool &IsSectionRelocation, uint64_t &SymbolAddress, int64_t &Addend,
     uint64_t &ExtractedValue, bool &Skip) const {
   Skip = false;