[gn] Enable stricter build flags

test/cctest/heap/test-heap.cc

 // Copyright 2012 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 5697 matching lines @@
   CcTest::CollectGarbage(NEW_SPACE);
   CcTest::CollectGarbage(NEW_SPACE);  // Ensure new space is empty.
   const size_t kSize = 1024;
   AllocateInSpace(isolate, kSize, NEW_SPACE);
   size_t counter2 = heap->NewSpaceAllocationCounter();
   CHECK_EQ(kSize, counter2 - counter1);
   CcTest::CollectGarbage(NEW_SPACE);
   size_t counter3 = heap->NewSpaceAllocationCounter();
   CHECK_EQ(0U, counter3 - counter2);
   // Test counter overflow.
-  size_t max_counter = -1;
+  size_t max_counter = static_cast<size_t>(-1);
   heap->set_new_space_allocation_counter(max_counter - 10 * kSize);
   size_t start = heap->NewSpaceAllocationCounter();
   for (int i = 0; i < 20; i++) {
     AllocateInSpace(isolate, kSize, NEW_SPACE);
     size_t counter = heap->NewSpaceAllocationCounter();
     CHECK_EQ(kSize, counter - start);
     start = counter;
   }
 }
 
@@ skipping 12 matching lines @@
   // TODO(ulan): replace all CHECK_LE with CHECK_EQ after v8:4148 is fixed.
   CHECK_LE(kSize, counter2 - counter1);
   CcTest::CollectGarbage(NEW_SPACE);
   size_t counter3 = heap->OldGenerationAllocationCounter();
   CHECK_EQ(0u, counter3 - counter2);
   AllocateInSpace(isolate, kSize, OLD_SPACE);
   CcTest::CollectGarbage(OLD_SPACE);
   size_t counter4 = heap->OldGenerationAllocationCounter();
   CHECK_LE(kSize, counter4 - counter3);
   // Test counter overflow.
-  size_t max_counter = -1;
+  size_t max_counter = static_cast<size_t>(-1);
   heap->set_old_generation_allocation_counter_at_last_gc(max_counter -
                                                          10 * kSize);
   size_t start = heap->OldGenerationAllocationCounter();
   for (int i = 0; i < 20; i++) {
     AllocateInSpace(isolate, kSize, OLD_SPACE);
     size_t counter = heap->OldGenerationAllocationCounter();
     CHECK_LE(kSize, counter - start);
     start = counter;
   }
 }
@@ skipping 875 matching lines @@
   CHECK(!heap->code_space()->FirstPage()->Contains(code->address()));
 
   // Ensure it's not in large object space.
   MemoryChunk* chunk = MemoryChunk::FromAddress(code->address());
   CHECK(chunk->owner()->identity() != LO_SPACE);
   CHECK(chunk->NeverEvacuate());
 }
 
 }  // namespace internal
 }  // namespace v8