[PATCH] [lld][ELF] rename TLV contentTypes for ELF

[kledzik at apple.com]

  >What happens on Darwin when for static executables, Does the call still get routed through the thunk ?
  Darwin does not support static executables.  The syscall interface is private, so all programs must be dynamic and link with libSystem.dylib to make POSIX/syscalls.

  Also, there are no linker optimizations/relaxations to change thread local variable access. It is always through a thunk call (which the compiler knows preserves all registers).

  >I think by default then Darwin follows a similiar model like the ELF global dynamic model ?
  Similar in flexibility, but the data structures are different.

http://llvm-reviews.chandlerc.com/D1482