Add test case for missing deopt sequence after forced deopt.

test/mjsunit/regress/regress-crbug-217858.js

Index: test/mjsunit/regress/regress-crbug-217858.js
diff --git a/test/mjsunit/regress/regress-crbug-173974.js b/test/mjsunit/regress/regress-crbug-217858.js
similarity index 91%
copy from test/mjsunit/regress/regress-crbug-173974.js
copy to test/mjsunit/regress/regress-crbug-217858.js
index 905bd6058a0ad0fe2ebe10e4c7dafbe9945cbe3b..8563e07eee9e1acbcdc8c5c28c461f2d27fad6f1 100644
--- a/test/mjsunit/regress/regress-crbug-173974.js
+++ b/test/mjsunit/regress/regress-crbug-217858.js
@@ -27,10 +27,14 @@
 
 // Flags: --allow-natives-syntax
 
+var r = /r/;
+var a = "";
 function f() {
-  var count = "";
-  count[0] --;
+  %OptimizeFunctionOnNextCall(f, "osr");
+  for (var i = 0; i < 1000000; i++) {
+    a += i.toString();
+    r[r] = function() {};
+  }
 }
-f();
-%OptimizeFunctionOnNextCall(f);
+
 f();