Checks for empty array case added before casting elements to FixedDoubleArray.

test/mjsunit/regress/regress-369450.js

Index: test/mjsunit/regress/regress-369450.js
diff --git a/test/mjsunit/regress/regress-empty-fixed-double-array.js b/test/mjsunit/regress/regress-369450.js
similarity index 55%
copy from test/mjsunit/regress/regress-empty-fixed-double-array.js
copy to test/mjsunit/regress/regress-369450.js
index 1db9e2b3e54e2abfddddd23f4ee6618ae438db20..e4523619f08407a532787976a7c36fd39a34c98f 100644
--- a/test/mjsunit/regress/regress-empty-fixed-double-array.js
+++ b/test/mjsunit/regress/regress-369450.js
@@ -4,12 +4,12 @@
 
 // Flags: --allow-natives-syntax --enable-slow-asserts
 
-function f(a, x) {
-  a.shift();
-  a[0] = x;
-}
-
-f([1], 1.1);
-f([1], 1.1);
-%OptimizeFunctionOnNextCall(f);
-f([1], 1.1);
+var v = [1.3];
+v.length = 0;
+
+var json = JSON.stringify(v);
+assertEquals("[]", json);
+
+Array.prototype[0] = 5.5;
+var arr = [].concat(v, [{}], [2.3]);
+assertEquals([{}, 2.3], arr);