Implement long negate instruction in the optimizing compiler.

- Add support for the neg-long (long integer two's
  complement negate) instruction in the optimizing compiler.
- Add a 64-bit NEG instruction (negq) to the x86-64
  assembler.
- Generate ARM, x86 and x86-64 code for integer HNeg nodes.
- Put neg-related tests into test/415-optimizing-arith-neg.

Change-Id: I1fbe9611e134408a6b8745d1df20ab6ffa5e50f2
diff --git a/test/Android.run-test.mk b/test/Android.run-test.mk
index 6822825..5b95beb 100644
--- a/test/Android.run-test.mk
+++ b/test/Android.run-test.mk
@@ -317,6 +317,7 @@
   412-new-array \
   413-regalloc-regression \
   414-optimizing-arith-sub \
+  415-optimizing-arith-neg \
   700-LoadArgRegs \
   800-smali