Implement local check elimination on basic blocks.

test/cctest/test-unique.cc

 // Copyright 2013 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 147 matching lines @@
   CHECK_EQ(3, set->size());
   set->Add(C, &zone);
   CHECK_EQ(3, set->size());
   set->Add(B, &zone);
   CHECK_EQ(3, set->size());
   set->Add(A, &zone);
   CHECK_EQ(3, set->size());
 }
 
 
+TEST(UniqueSet_Remove) {
+  CcTest::InitializeVM();
+  MAKE_HANDLES_AND_DISALLOW_ALLOCATION;
+  MAKE_UNIQUES_A_B_C;
+
+  Zone zone(isolate);
+
+  UniqueSet<String>* set = new(&zone) UniqueSet<String>();
+
+  set->Add(A, &zone);
+  set->Add(B, &zone);
+  set->Add(C, &zone);
+  CHECK_EQ(3, set->size());
+
+  set->Remove(A);
+  CHECK_EQ(2, set->size());
+  CHECK(!set->Contains(A));
+  CHECK(set->Contains(B));
+  CHECK(set->Contains(C));
+
+  set->Remove(A);
+  CHECK_EQ(2, set->size());
+  CHECK(!set->Contains(A));
+  CHECK(set->Contains(B));
+  CHECK(set->Contains(C));
+
+  set->Remove(B);
+  CHECK_EQ(1, set->size());
+  CHECK(!set->Contains(A));
+  CHECK(!set->Contains(B));
+  CHECK(set->Contains(C));
+
+  set->Remove(C);
+  CHECK_EQ(0, set->size());
+  CHECK(!set->Contains(A));
+  CHECK(!set->Contains(B));
+  CHECK(!set->Contains(C));
+}
+
+
 TEST(UniqueSet_Contains) {
   CcTest::InitializeVM();
   MAKE_HANDLES_AND_DISALLOW_ALLOCATION;
   MAKE_UNIQUES_A_B_C;
 
   Zone zone(isolate);
 
   UniqueSet<String>* set = new(&zone) UniqueSet<String>();
 
   CHECK_EQ(0, set->size());
@@ skipping 322 matching lines @@
 
       UniqueSet<String>* result = set1->Union(set2, &zone);
       UniqueSet<String>* expected = MakeSet(&zone, i | j, elements);
 
       CHECK(result->Equals(expected));
       CHECK(expected->Equals(result));
     }
   }
 }