[heap] Minor MC: Add evacuation phase

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/context-slot-cache.h"
 #include "src/base/bits.h"
@@ skipping 1427 matching lines @@
 
   LOG(isolate_, ResourceEvent("markcompact", "end"));
 
   MarkCompactEpilogue();
 
   if (FLAG_allocation_site_pretenuring) {
     EvaluateOldSpaceLocalPretenuring(size_of_objects_before_gc);
   }
 }
 
-void Heap::MinorMarkCompact() { UNREACHABLE(); }
+void Heap::MinorMarkCompact() {
+  TRACE_GC(tracer(), GCTracer::Scope::MINOR_MC);
+  mark_compact_collector()->CollectGarbageInYoungGeneration();
+}
 
 void Heap::MarkCompactEpilogue() {
   TRACE_GC(tracer(), GCTracer::Scope::MC_EPILOGUE);
   gc_state_ = NOT_IN_GC;
 
   isolate_->counters()->objs_since_last_full()->Set(0);
 
   incremental_marking()->Epilogue();
 
   PreprocessStackTraces();
@@ skipping 5002 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8