Update lib/Target/ARM/README.txt

One of the lib/Target/ARM/README.txt items can be removed as this is
currently the output I get:

  .globl my_abs
  .align 2
  .type my_abs,%function
  add r1, r0, r0, asr #31
  eor r0, r1, r0, asr #31
  bx lr
  .size my_abs, .-my_abs


abs.patch (874 Bytes)

Thanks, removed. Most low-level codegen issues like this are best reported to the llvmdev mailing list. Thanks!