[turbofan] Add support for eager/soft deoptimization reasons.

src/deoptimize-reason.cc

+// Copyright 2016 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/deoptimize-reason.h"
+
+namespace v8 {
+namespace internal {
+
+std::ostream& operator<<(std::ostream& os, DeoptimizeReason reason) {
+  switch (reason) {
+#define DEOPTIMIZE_REASON(Name, message) \
+  case DeoptimizeReason::k##Name:        \
+    return os << #Name;
+    DEOPTIMIZE_REASON_LIST(DEOPTIMIZE_REASON)
+#undef DEOPTIMIZE_REASON
+  }
+  UNREACHABLE();
+  return os;
+}
+
+size_t hash_value(DeoptimizeReason reason) {
+  return static_cast<uint8_t>(reason);
+}
+
+char const* const DeoptimizeReasonToString(DeoptimizeReason reason) {
+  static char const* kDeoptimizeReasonStrings[] = {
+#define DEOPTIMIZE_REASON(Name, message) message,
+      DEOPTIMIZE_REASON_LIST(DEOPTIMIZE_REASON)
+#undef DEOPTIMIZE_REASON
+  };
+  size_t const index = static_cast<size_t>(reason);
+  DCHECK_LT(index, arraysize(kDeoptimizeReasonStrings));
+  return kDeoptimizeReasonStrings[index];
+}
+
+}  // namespace internal
+}  // namespace v8