dropped reporting of mov[s] r0, r0 as NOP

Currently `mov[s] r0, r0` is reported as a `I_NOP` but `movs` is different from a `nop` and can require special treatment.
Consider the following example from `libc` that shows how a `movs r0, r0` is useful.

```
ENTRY(gettid)
    .save   {r4, r7}
    stmfd   sp!, {r4, r7}
    ldr     r7, =__NR_gettid
    swi     #0
    ldmfd   sp!, {r4, r7}
    movs    r0, r0
    bxpl    lr
    b       __set_syscall_errno
```