[lld] [ELF] [X86_64] Update TODO.rst list wrt r218633

[rafaelauler]

Summary

This patch updates the remaining tasks in the X86_64 ELF lld backend after the
commit that handles general dynamic TLS relocations.

[emaste]

lib/ReaderWriter/ELF/X86_64/TODO.rst

45–46

Should the completed ones just be removed from the TODO list?

[rafaelauler]

You're right, thanks. Changed.

[rafaelauler]

Committed r219350.

lib/ReaderWriter/ELF/X86_64/TODO.rst

 ELF x86-64
 ~~~~~~~~~~
 
 Unimplemented Features
 ######################
 
 * Code models other than the small code model
-* Fully dynamic TLS
 * TLS strength reduction
 
 Unimplemented Relocations
 #########################
 
 All of these relocations are defined in:
 http://www.x86-64.org/documentation/abi.pdf
 

 <<<<<<<<<<<<<<<<<<<<<<<<<<
 
 * R_X86_64_GOTOFF32
 * R_X86_64_GOTOFF64
 
 Global Dynamic Thread Local Storage Relocs
 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
 
-These relocations will take more effort to implement. Their implementation
-should be contained in lib/ReaderWriter/ELF/X86_64/{X86_64RelocationPass.cpp,X86_64RelocationHandler.cpp}.
+These relocations take more effort to implement, but some of them are done.
+Their implementation lives in lib/ReaderWriter/ELF/X86_64/{X86_64RelocationPass.cpp,X86_64RelocationHandler.cpp}.
 
 Documentation on these relocations can be found in:
 http://www.akkadia.org/drepper/tls.pdf
 
-* R_X86_64_DTPMOD64
-* R_X86_64_DTPOFF64
-* R_X86_64_TLSGD
 * R_X86_64_GOTPC32_TLSDESC
 * R_X86_64_TLSDESC_CALL
 * R_X86_64_TLSDESC