[AArch64] Initial ELF/AArch64 Support

This patch adds the initial ELF/AArch64 support to lld. Only a basic "Hello
World" app has been successfully tested for both dynamic and static compiling.

Differential Revision: http://reviews.llvm.org/D4778
Patch by Daniel Stewart <stewartd@codeaurora.org>!

llvm-svn: 215544
diff --git a/lld/docs/open_projects.rst b/lld/docs/open_projects.rst
index 6d2b535..92a26b0 100644
--- a/lld/docs/open_projects.rst
+++ b/lld/docs/open_projects.rst
@@ -7,6 +7,7 @@
 .. include:: ../lib/Core/TODO.txt
 .. include:: ../lib/Driver/TODO.rst
 .. include:: ../lib/ReaderWriter/ELF/X86_64/TODO.rst
+.. include:: ../lib/ReaderWriter/ELF/AArch64/TODO.rst
 .. include:: ../tools/lld/TODO.txt
 
 Documentation TODOs