Fix comparison between doubles and hex numeric strings

Summary: This pattern already exists in here for ints & hex numerics,
duplicate it for doubles.

Closes #4252

Reviewed By: @JoelMarcey

Differential Revision: D1684171

Signature: t1:1684171:1416259812:b74d9ed40854f0cc3924226a48dc3676e04432d3
Remove nullptr check from SmartPtr::operator->()

Summary: If the null pointer exception fires, it's just as much of
a bug as the sigsegv, so move faster and crash harder.

Reviewed By: @markw65

Differential Revision: D1684957

Signature: t1:1684957:1416244268:3f973856bda05f2009620e065bf80029662cc85b
Add tests for Hdf -> Ini name conversion code

Summary: I thought it was misbehaving on Eval.JitLLVM so I wrote a test to make
fixing it more convenient. It turned out to be doing the right thing all along,
but tests are cool even when they don't fail.

Reviewed By: @JoelMarcey

Differential Revision: D1678147

Signature: t1:1678147:1415842877:93b51c15749ae84e0414fc49a033de0fb68388c1