Improve escape analysis

test/mjsunit/compiler/escape-analysis-9.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 10 matching lines @@
 // 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 --turbo-escape
 //
 
-function f(a) {
-  "use strict";
+function f() {
   return arguments;
 }
 
 function g(a) {
   "use strict";
-  var x = f(1,2,3);
+  var o = f(1,2);
   if (a) {
-    x[1] = 5;
+    o[0] = 5;
   } else {
-    x[1] = 7;
+    o[0] = 7;
   }
 
-  return x[1];
+  return o[0];
 }
 
 assertEquals(7, g());
 assertEquals(7, g());
 %OptimizeFunctionOnNextCall(g);
+assertEquals(5, g(true));
+assertEquals(7, g(false));
 assertEquals(7, g());