Remove special handling of TLS/NOTE/RELRO sections.

[ruiu]

Summary

We were handling TLS/NOTE/RELRO sections in a special manner when
linker scripts are given. But I think we don't really need this --
we generally don't make a guess if linker scripts are given and do
exactly what is instructed to do. Our stance is, if you want to force
some layout, you need to give complete instructions to the linker.

[evgeny777]

LGTM. Actually I planned this myself for one of the next patches.

[ruiu]

I'll submit it tomorrow morning, but feel free to submit yourself if you need it now.

[evgeny777]

Committed in r276731

ELF/LinkerScript.cpp

void LinkerScript<ELFT>::assignAddresses(
   Out<ELFT>::ElfHeader->setVA(MinVA);
   Out<ELFT>::ProgramHeaders->setVA(Out<ELFT>::ElfHeader->getSize() + MinVA);
 }
 
 template <class ELFT>
 std::vector<PhdrEntry<ELFT>>
 LinkerScript<ELFT>::createPhdrs(ArrayRef<OutputSectionBase<ELFT> *> Sections) {
   std::vector<PhdrEntry<ELFT>> Ret;
-  PhdrEntry<ELFT> *TlsPhdr = nullptr;
-  PhdrEntry<ELFT> *NotePhdr = nullptr;
-  PhdrEntry<ELFT> *RelroPhdr = nullptr;
 
   for (const PhdrsCommand &Cmd : Opt.PhdrsCommands) {
     Ret.emplace_back(Cmd.Type, Cmd.Flags == UINT_MAX ? PF_R : Cmd.Flags);
     PhdrEntry<ELFT> &Phdr = Ret.back();
 
     if (Cmd.HasFilehdr)
       Phdr.add(Out<ELFT>::ElfHeader);
     if (Cmd.HasPhdrs)
       Phdr.add(Out<ELFT>::ProgramHeaders);
 
     switch (Cmd.Type) {
     case PT_INTERP:
       if (Out<ELFT>::Interp)
         Phdr.add(Out<ELFT>::Interp);
       break;
     case PT_DYNAMIC:
       if (isOutputDynamic<ELFT>()) {
         Phdr.H.p_flags = toPhdrFlags(Out<ELFT>::Dynamic->getFlags());
         Phdr.add(Out<ELFT>::Dynamic);
       }
       break;
-    case PT_TLS:
-      TlsPhdr = &Phdr;
-      break;
-    case PT_NOTE:
-      NotePhdr = &Phdr;
-      break;
-    case PT_GNU_RELRO:
-      RelroPhdr = &Phdr;
-      break;
     case PT_GNU_EH_FRAME:
       if (!Out<ELFT>::EhFrame->empty() && Out<ELFT>::EhFrameHdr) {
         Phdr.H.p_flags = toPhdrFlags(Out<ELFT>::EhFrameHdr->getFlags());
         Phdr.add(Out<ELFT>::EhFrameHdr);
       }
       break;
     }
   }
 
   PhdrEntry<ELFT> *Load = nullptr;
   uintX_t Flags = PF_R;
   for (OutputSectionBase<ELFT> *Sec : Sections) {
     if (!(Sec->getFlags() & SHF_ALLOC))
       break;
 
-    if (TlsPhdr && (Sec->getFlags() & SHF_TLS))
-      TlsPhdr->add(Sec);
-
-    if (!needsPtLoad<ELFT>(Sec))
-      continue;
-
     std::vector<size_t> PhdrIds = getPhdrIndices(Sec->getName());
     if (!PhdrIds.empty()) {
       // Assign headers specified by linker script
       for (size_t Id : PhdrIds) {
         Ret[Id].add(Sec);
         if (Opt.PhdrsCommands[Id].Flags == UINT_MAX)
           Ret[Id].H.p_flags |= toPhdrFlags(Sec->getFlags());
       }
     } else {
       // If we have no load segment or flags've changed then we want new load
       // segment.
       uintX_t NewFlags = toPhdrFlags(Sec->getFlags());
       if (Load == nullptr || Flags != NewFlags) {
         Load = &*Ret.emplace(Ret.end(), PT_LOAD, NewFlags);
         Flags = NewFlags;
       }
       Load->add(Sec);
     }
-
-    if (RelroPhdr && isRelroSection(Sec))
-      RelroPhdr->add(Sec);
-    if (NotePhdr && Sec->getType() == SHT_NOTE)
-      NotePhdr->add(Sec);
   }
   return Ret;
 }
 
 template <class ELFT>
 ArrayRef<uint8_t> LinkerScript<ELFT>::getFiller(StringRef Name) {
   for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands)
     if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base.get()))