Make HCheckPrototypeMaps compatible with parallel recompilation.

test/mjsunit/parallel-recompilation.js

Index: test/mjsunit/parallel-recompilation.js
diff --git a/test/mjsunit/regress/regress-crbug-168545.js b/test/mjsunit/parallel-recompilation.js
similarity index 78%
copy from test/mjsunit/regress/regress-crbug-168545.js
copy to test/mjsunit/parallel-recompilation.js
index acc065e41101325dd9b105f73e50748b1c9cff13..75403656f6a5b63e259251631521d34b85fdb2f2 100644
--- a/test/mjsunit/regress/regress-crbug-168545.js
+++ b/test/mjsunit/parallel-recompilation.js
@@ -25,10 +25,20 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+// Flags: --allow-natives-syntax 
+// Flags: --parallel-recompilation --manual-parallel-recompilation
+
+function f(foo) { return foo.bar(); }
+
 var o = {};
-Object.defineProperty(o, "length", { get: function() { throw "bail"; }});
-assertThrows("new Int16Array(o);");
+o.__proto__ = { __proto__: { bar: function() { return 1; } } };
+
+assertEquals(1, f(o));
+assertEquals(1, f(o));
+
+%ForceParallelRecompile(f);
+// Change the prototype chain during optimization.
+o.__proto__.__proto__ = { bar: function() { return 2; } };
+%InstallRecompiledCode(f);
 
-var a = [];
-Object.defineProperty(a, "0", { get: function() { throw "bail"; }});
-assertThrows("new Int16Array(a);");
+assertEquals(2, f(o));