Support float & double negation in the optimizing compiler.

- Add support for the neg-float and neg-double Dex
  instructions in the optimizing compiler.
- Generate x86, x86-64 and ARM (but not ARM64) code for
  float and double HNeg nodes.
- Add related tests to test/415-optimizing-arith-neg.

Change-Id: I29739a86e13dbe6f64e191641d01637c867cba6c
5 files changed