Add kLastTemperature as temperature high bound (#10044)

Summary:
Only used as temperature high bound for current code, may
increase with more temperatures added.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10044

Test Plan: ci

Reviewed By: siying

Differential Revision: D36633410

Pulled By: jay-zhuang

fbshipit-source-id: eecdfa7623c31778c31d789902eacf78aad7b482

db/db_test2.cc

@@ -6883,6 +6883,11 @@ TEST_F(DBTest2, BottommostTemperatureUniversal) {
   ASSERT_EQ(size, 0);
   size = GetSstSizeHelper(Temperature::kCold);
   ASSERT_GT(size, 0);
+
+  // kLastTemperature is an invalid temperature
+  options.bottommost_temperature = Temperature::kLastTemperature;
+  s = TryReopen(options);
+  ASSERT_TRUE(s.IsIOError());
 }
 
 TEST_F(DBTest2, LastLevelStatistics) {

include/rocksdb/advanced_options.h

@@ -223,6 +223,7 @@ enum class Temperature : uint8_t {
   kHot = 0x04,
   kWarm = 0x08,
   kCold = 0x0C,
+  kLastTemperature,
 };
 
 // The control option of how the cache tiers will be used. Currently rocksdb