[ELF] TBSS section has to be special cased so that it doesnot occupy memory space

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@183815 91177308-0d34-0410-b5e6-96231b3b80d8
[ELF] NMAGIC support :  Find the BSS section to setup the virtual address of _end.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@183816 91177308-0d34-0410-b5e6-96231b3b80d8
[ELF][X86_64] Create GOT entries for external TLS symbols properly without Segfaults.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@183817 91177308-0d34-0410-b5e6-96231b3b80d8