message: Move shrinker log to TRACE
  Summary: As title.
diff: #include "ConstructorParams.h"
  #include "RandomForest.h"
  #include "RegisterAllocation.h"
  +#include "Trace.h"
  namespace shrinker {
  @@ -43,7 +44,7 @@ Shrinker::ShrinkerForest load(const std::string& filename) {
  content = buffer.str();
  }
  if (content.empty()) {
  - std::cerr << "No shrinker forest: " << filename << std::endl;
  + TRACE(MMINL, 1, "No shrinker forest: %s", filename.c_str());
  return Shrinker::ShrinkerForest(); // Empty forest accepts everything.
  }
  return Shrinker::ShrinkerForest::deserialize(
  