[ELF] - Refactor of tls_index implementation for tls local dynamic model.

Patch contains the next 2 changes:
1) static variable Out<ELFT>::LocalModuleTlsIndexOffset moved to Out<ELFT>::Got. At fact there is no meaning for it to be separated from GOT class because at each place of using it anyways needs to call GOT`s getVA(). Also it is impossible to have that offset and not have GOT.
2) addLocalModuleTlsIndex -> addLocalModelTlsIndex (word "Module" changed to "Model"). Not sure was it a mistype or not but I think that update is closer to Urlich terminology.

Differential revision: http://reviews.llvm.org/D15113

llvm-svn: 254428
diff --git a/lld/ELF/OutputSections.h b/lld/ELF/OutputSections.h
index dea9bb3..a676ce3 100644
--- a/lld/ELF/OutputSections.h
+++ b/lld/ELF/OutputSections.h
@@ -119,7 +119,7 @@
   void writeTo(uint8_t *Buf) override;
   void addEntry(SymbolBody *Sym);
   void addDynTlsEntry(SymbolBody *Sym);
-  uint32_t addLocalModuleTlsIndex();
+  bool addLocalModelTlsIndex();
   bool empty() const { return Entries.empty(); }
   uintX_t getEntryAddr(const SymbolBody &B) const;
 
@@ -133,8 +133,11 @@
   // the number of reserved entries. This method is MIPS-specific.
   unsigned getMipsLocalEntriesNum() const;
 
+  uint32_t getLocalTlsIndexVA() { return getVA() + LocalTlsIndexOff; }
+
 private:
   std::vector<const SymbolBody *> Entries;
+  uint32_t LocalTlsIndexOff = -1;
 };
 
 template <class ELFT>
@@ -430,7 +433,6 @@
   static SymbolTableSection<ELFT> *DynSymTab;
   static SymbolTableSection<ELFT> *SymTab;
   static Elf_Phdr *TlsPhdr;
-  static uint32_t LocalModuleTlsIndexOffset;
 };
 
 template <class ELFT> DynamicSection<ELFT> *Out<ELFT>::Dynamic;
@@ -452,7 +454,6 @@
 template <class ELFT> SymbolTableSection<ELFT> *Out<ELFT>::DynSymTab;
 template <class ELFT> SymbolTableSection<ELFT> *Out<ELFT>::SymTab;
 template <class ELFT> typename Out<ELFT>::Elf_Phdr *Out<ELFT>::TlsPhdr;
-template <class ELFT> uint32_t Out<ELFT>::LocalModuleTlsIndexOffset = -1;
 
 } // namespace elf2
 } // namespace lld