[ELF] Update to llvm change.

llvm-svn: 171652
diff --git a/lld/lib/ReaderWriter/ELF/WriterELF.cpp b/lld/lib/ReaderWriter/ELF/WriterELF.cpp
index d410da2..a5459a3 100644
--- a/lld/lib/ReaderWriter/ELF/WriterELF.cpp
+++ b/lld/lib/ReaderWriter/ELF/WriterELF.cpp
@@ -1208,7 +1208,7 @@
          bool is64Bits>
 class ELFProgramHeader : public Chunk<target_endianness, max_align, is64Bits> {
 public:
-  typedef Elf_Phdr<target_endianness, max_align, is64Bits> Elf_Phdr;
+  typedef Elf_Phdr_Impl<target_endianness, max_align, is64Bits> Elf_Phdr;
 
   ELFProgramHeader()
   : Chunk<target_endianness, max_align, is64Bits>(