[heap] Introduce enum of garbage collection reasons.

test/cctest/heap/test-alloc.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 73 matching lines @@
 
   // Return success.
   return heap->true_value();
 }
 
 
 Handle<Object> v8::internal::HeapTester::TestAllocateAfterFailures() {
   // Similar to what the CALL_AND_RETRY macro does in the last-resort case, we
   // are wrapping the allocator function in an AlwaysAllocateScope.  Test that
   // all allocations succeed immediately without any retry.
-  CcTest::heap()->CollectAllAvailableGarbage("panic");
+  CcTest::CollectAllAvailableGarbage();
   AlwaysAllocateScope scope(CcTest::i_isolate());
   return handle(AllocateAfterFailures().ToObjectChecked(), CcTest::i_isolate());
 }
 
 
 HEAP_TEST(StressHandles) {
   v8::HandleScope scope(CcTest::isolate());
   v8::Local<v8::Context> env = v8::Context::New(CcTest::isolate());
   env->Enter();
   Handle<Object> o = TestAllocateAfterFailures();
@@ skipping 137 matching lines @@
       code_range.FreeRawMemory(blocks[index].base, blocks[index].size);
       current_allocated -= blocks[index].size;
       if (index < blocks.length() - 1) {
         blocks[index] = blocks.RemoveLast();
       } else {
         blocks.RemoveLast();
       }
     }
   }
 }