ELF support for LLD writer. The writer at present emits ELF header and section 
table header. Skeleton code for ReferenceKinds.
Credits:
Doxygen by  Michael Spencer.
Origianl implementation from Macho by Sidney Manning.
Templatization, implementation of section header chunks, string table, ELF header by Hemant Kulkarni.

llvm-svn: 163906
diff --git a/lld/lib/ReaderWriter/ELF/ReaderELF.cpp b/lld/lib/ReaderWriter/ELF/ReaderELF.cpp
index b6d4978..9b15b2a 100644
--- a/lld/lib/ReaderWriter/ELF/ReaderELF.cpp
+++ b/lld/lib/ReaderWriter/ELF/ReaderELF.cpp
@@ -214,7 +214,7 @@
       return (Alignment(Symbol->st_value));
     }
 
-    return Alignment(1);
+    return Alignment(llvm::Log2_64(Section->sh_addralign));
   }
 
   // Do we have a choice for ELF?  All symbols