Merge bitcoin/bitcoin#24461: build: Minor leveldb subtree update

1b20109b04 Squashed 'src/leveldb/' changes from f8ae182c1e..330dd6235f (MarcoFalke)

Pull request description:

  A minor change to:

  * Consistently use the same symbol names in the whole project.
  * Fix compiling with C++20.

ACKs for top commit:
  fanquake:
    ACK fa0c32eb74

Tree-SHA512: b5d4540dd621cf4aa8caac811bae03bb74e502a31dbdda9354182e4caa39905550e62ad3cf8ea7d7f9bfc3e5120d119d34ab0f1e633716ec8089876037cbf192

src/leveldb/util/env_posix.cc

@@ -850,7 +850,7 @@ class SingletonEnv {
  public:
   SingletonEnv() {
 #if !defined(NDEBUG)
-    env_initialized_.store(true, std::memory_order::memory_order_relaxed);
+    env_initialized_.store(true, std::memory_order_relaxed);
 #endif  // !defined(NDEBUG)
     static_assert(sizeof(env_storage_) >= sizeof(EnvType),
                   "env_storage_ will not fit the Env");
@@ -867,7 +867,7 @@ class SingletonEnv {
 
   static void AssertEnvNotInitialized() {
 #if !defined(NDEBUG)
-    assert(!env_initialized_.load(std::memory_order::memory_order_relaxed));
+    assert(!env_initialized_.load(std::memory_order_relaxed));
 #endif  // !defined(NDEBUG)
   }
 

src/leveldb/util/env_windows.cc

@@ -798,7 +798,7 @@ class SingletonEnv {
  public:
   SingletonEnv() {
 #if !defined(NDEBUG)
-    env_initialized_.store(true, std::memory_order::memory_order_relaxed);
+    env_initialized_.store(true, std::memory_order_relaxed);
 #endif  // !defined(NDEBUG)
     static_assert(sizeof(env_storage_) >= sizeof(EnvType),
                   "env_storage_ will not fit the Env");
@@ -815,7 +815,7 @@ class SingletonEnv {
 
   static void AssertEnvNotInitialized() {
 #if !defined(NDEBUG)
-    assert(!env_initialized_.load(std::memory_order::memory_order_relaxed));
+    assert(!env_initialized_.load(std::memory_order_relaxed));
 #endif  // !defined(NDEBUG)
   }