Refactor all instances of `typedef y x` to the C++11 `using x = y` syntax.

src/IceELFObjectWriter.h

 //===- subzero/src/IceELFObjectWriter.h - ELF object writer -----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 79 matching lines @@
   /// This is used as an array index so should start at 0 and be contiguous.
   enum SectionType { ROData = 0, Data, BSS, NumSectionTypes };
 
 private:
   GlobalContext &Ctx;
   ELFStreamer &Str;
   bool SectionNumbersAssigned = false;
   bool ELF64;
 
   // All created sections, separated into different pools.
-  typedef std::vector<ELFSection *> SectionList;
-  typedef std::vector<ELFTextSection *> TextSectionList;
-  typedef std::vector<ELFDataSection *> DataSectionList;
-  typedef std::vector<ELFRelocationSection *> RelSectionList;
+  using SectionList = std::vector<ELFSection *>;
+  using TextSectionList = std::vector<ELFTextSection *>;
+  using DataSectionList = std::vector<ELFDataSection *>;
+  using RelSectionList = std::vector<ELFRelocationSection *>;
   TextSectionList TextSections;
   RelSectionList RelTextSections;
   DataSectionList DataSections;
   RelSectionList RelDataSections;
   DataSectionList RODataSections;
   RelSectionList RelRODataSections;
   DataSectionList BSSSections;
 
   // Handles to special sections that need incremental bookkeeping.
   ELFSection *NullSection;
@@ skipping 50 matching lines @@
 
   /// Write the ELF file header with the given information about sections.
   template <bool IsELF64>
   void writeELFHeaderInternal(Elf64_Off SectionHeaderOffset,
                               SizeT SectHeaderStrIndex, SizeT NumSections);
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEELFOBJECTWRITER_H