Merge bitcoin/bitcoin#25109: Strengthen AssertLockNotHeld assertions

436ce0233c sync.h: strengthen AssertLockNotHeld assertion (Anthony Towns)
7d73f58e9c Increase threadsafety annotation coverage (Anthony Towns)

Pull request description:

  This changes `AssertLockNotHeld` so that it is annotated with the negative capability for the mutex it refers to. clang applies negative capabilities recursively, so this helps avoid forgetting to annotate functions.

  Note that this can't reasonably be used for globals, because clang would require every function to be annotated with `EXCLUSIVE_LOCKS_REQUIRED(!g_mutex)` for each global mutex. At present, the only global mutexes that use `AssertLockNotHeld` are `RecursiveMutex` so we treat that as an exception in order to avoid having to add an excessive number of negative annotations.

ACKs for top commit:
  vasild:
    ACK 436ce0233c
  MarcoFalke:
    review ACK 436ce0233c 🌺

Tree-SHA512: 5f16d098790a36b5277324d5ee89cdc87033c19b11c7943c2f630a41c2e3998eb39d356a763e857f4d8fefb6c0c02291f720bb6769bcbdf5e2cd765bf266ab8c

src/random.cpp

@@ -374,7 +374,7 @@ public:
     {
     }
 
-    void AddEvent(uint32_t event_info) noexcept
+    void AddEvent(uint32_t event_info) noexcept EXCLUSIVE_LOCKS_REQUIRED(!m_events_mutex)
     {
         LOCK(m_events_mutex);
 
@@ -388,7 +388,7 @@ public:
     /**
      * Feed (the hash of) all events added through AddEvent() to hasher.
      */
-    void SeedEvents(CSHA512& hasher) noexcept
+    void SeedEvents(CSHA512& hasher) noexcept EXCLUSIVE_LOCKS_REQUIRED(!m_events_mutex)
     {
         // We use only SHA256 for the events hashing to get the ASM speedups we have for SHA256,
         // since we want it to be fast as network peers may be able to trigger it repeatedly.
@@ -407,7 +407,7 @@ public:
      *
      * If this function has never been called with strong_seed = true, false is returned.
      */
-    bool MixExtract(unsigned char* out, size_t num, CSHA512&& hasher, bool strong_seed) noexcept
+    bool MixExtract(unsigned char* out, size_t num, CSHA512&& hasher, bool strong_seed) noexcept EXCLUSIVE_LOCKS_REQUIRED(!m_mutex)
     {
         assert(num <= 32);
         unsigned char buf[64];