[runtime function] Fix IndexOf when start is -Infinity

src/runtime/runtime-array.cc

Index: src/runtime/runtime-array.cc
diff --git a/src/runtime/runtime-array.cc b/src/runtime/runtime-array.cc
index 5538fb4c28afc84838552b8bdc36bc8f306bd12b..f1002c82c6c93216cb54ad7a8aaa2526867bd888 100644
--- a/src/runtime/runtime-array.cc
+++ b/src/runtime/runtime-array.cc
@@ -568,7 +568,13 @@ RUNTIME_FUNCTION(Runtime_ArrayIndexOf) {
                                        Object::ToInteger(isolate, from_index));
     double fp = from_index->Number();
     if (fp > len) return Smi::FromInt(-1);
-    start_from = static_cast<int64_t>(fp);
+    if (V8_LIKELY(fp >=
+                  static_cast<double>(std::numeric_limits<int64_t>::min()))) {
+      DCHECK(fp < std::numeric_limits<int64_t>::max());
+      start_from = static_cast<int64_t>(fp);
+    } else {
+      start_from = fp = std::numeric_limits<int64_t>::min();

[Jakob Kummerow, 2017/05/09 15:04:23]

nit: assigning fp is unnecessary.

[predrag.rudic, 2017/05/09 15:15:40]

Acknowledged.

+    }
   }
 
   int64_t index;