Added transform for ABS(NABS(X)) and NABS(ABS(X))

[dinesh.d]

Summary

This removes TODO added in http://reviews.llvm.org/D3658

The patch transforms

ABS(NABS(X)) -> ABS(X)
NABS(ABS(X)) -> NABS(X)

[dinesh.d]

gentle ping

[chandlerc]

LGTM

I wouldn't bother re-testing all the permutations of the 'icmp' representation -- that code should already be well tested by existing checks? Still, not a big deal, just trying to minimize the redundancy in the testing.

[dinesh.d]

Thanks,

I had submitted similar patch [http://reviews.llvm.org/D3658] with all permutations of icmp.
This was just followup patch.

I am submitting it as it is. But if you care, I can remove few test cases for both changes.
In that case, we may not to add new file [abs_abs.ll], which I have added just because
there were too many test cases to add.

[dinesh.d]

Closed by commit rL210782 (authored by dinesh).