[arm64][turbofan] Fix implementation of Float64Min.

test/mjsunit/compiler/regress-4206.js

Index: test/mjsunit/compiler/regress-4206.js
diff --git a/test/mjsunit/compiler/regress-4206.js b/test/mjsunit/compiler/regress-4206.js
new file mode 100644
index 0000000000000000000000000000000000000000..742ed5dfe505532a506eeccafba27dcc9dc7c035
--- /dev/null
+++ b/test/mjsunit/compiler/regress-4206.js
@@ -0,0 +1,28 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+function Module(stdlib) {
+  "use asm";
+  function TernaryMin(a, b) {
+    a=+(a);
+    b=+(b);
+    return (+((a < b) ? a : b));
+  }
+  function TernaryMax(a, b) {
+    a=+(a);
+    b=+(b);
+    return (+((b < a) ? a : b));
+  }
+  return { TernaryMin: TernaryMin,
+           TernaryMax: TernaryMax };
+}
+var min = Module(this).TernaryMin;
+var max = Module(this).TernaryMax;
+
+assertEquals(0.0, min(-0.0, 0.0));
+assertEquals(0.0, min(NaN, 0.0));
+assertEquals(-0.0, min(NaN, -0.0));
+assertEquals(-0.0, max(0.0, -0.0));
+assertEquals(0.0, max(NaN, 0.0));
+assertEquals(-0.0, max(NaN, -0.0));