[turbofan] Unstable prototype maps are not supported currently.

test/mjsunit/regress/regress-crbug-557807.js

Index: test/mjsunit/regress/regress-crbug-557807.js
diff --git a/test/mjsunit/compiler/regress-491578.js b/test/mjsunit/regress/regress-crbug-557807.js
similarity index 68%
copy from test/mjsunit/compiler/regress-491578.js
copy to test/mjsunit/regress/regress-crbug-557807.js
index c27570456c31e9a191fe1f4f1ea17b80f29de98e..a96bc990031d4b763b13022fb2d1223088764b38 100644
--- a/test/mjsunit/compiler/regress-491578.js
+++ b/test/mjsunit/regress/regress-crbug-557807.js
@@ -4,12 +4,8 @@
 
 // Flags: --allow-natives-syntax
 
-function foo(x) {
-  if (x === undefined) return;
-  while (true) {
-    while (1 || 2) { }
-    f();
-  }
-}
+function bar() { return { __proto__: this }; }
+function foo(a) { a[0] = 0.3; }
+foo(bar());
 %OptimizeFunctionOnNextCall(foo);
-foo();
+foo(bar());