Fix failures after div support.

- We need to special case divide by -1 because of x86.
- Disable div test on arm64, which does not support div yet.

Change-Id: I07e137cb555a958b02a6c4070f296503b7e30bae
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 6ee4dfc..a57bbdb 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -1715,7 +1715,12 @@
   HDiv(Primitive::Type result_type, HInstruction* left, HInstruction* right)
       : HBinaryOperation(result_type, left, right) {}
 
-  virtual int32_t Evaluate(int32_t x, int32_t y) const { return x / y; }
+  virtual int32_t Evaluate(int32_t x, int32_t y) const {
+    // Our graph structure ensures we never have 0 for `y` during constant folding.
+    DCHECK_NE(y, 0);
+    // Special case -1 to avoid getting a SIGFPE on x86.
+    return (y == -1) ? -x : x / y;
+  }
   virtual int64_t Evaluate(int64_t x, int64_t y) const { return x / y; }
 
   DECLARE_INSTRUCTION(Div);