Bugfix in check elimination with a regression test.

test/mjsunit/regress/compare-map-elim1.js

 // Copyright 2010 the V8 project authors. All rights reserved.
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 //
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 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (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 --check-elimination
 
-a = {
-  f: function() { this.y = 3; }
-};
-b = {
-  f: function() { this.y = 4; }
-};
 
-function x(z) {
-  return z.f();
+function foo(o) {
+  return o.foo1;
 }
 
-x(a);
-x(b);
-x(a);
-x(b);
-x(a);
-x(b);
+function getter() {
+  return this.x + this.z + foo2(this);
+}
 
-%OptimizeFunctionOnNextCall(x)
+function foo2(o) {
+  return o.a;
+}
 
-x(a);
-x(b);
+var o1 = {z:0, x:1};
+var o2 = {z:0, a:1.5, x:1};
+var o3 = {z:0, a:1.5};
+Object.defineProperty(o1, "foo1", {get:getter});
+Object.defineProperty(o2, "foo1", {get:getter});
+
+foo(o1);
+foo(o1);
+foo(o2);
+%ClearFunctionTypeFeedback(foo2);
+foo2(o2);
+foo2(o2);
+foo2(o3);
+%OptimizeFunctionOnNextCall(foo);
+foo(o1);