QtTsan: maintain enumerator values for non-TSAN builds

... by moving the recently-added ReadLock enumerator to the end, so it
won't change the values of MutexWriteReentrant etc. The values appear
to be unused, but there's no reason to risk anything here.

Also move the TSAN-build enumerator, even though it has an initializer.
For consistency.

Amends 97bd609.

Found in API-review.

Pick-to: 6.11
Change-Id: I0db06d572119b64d6d3d238b27542c32194855c0
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

Author: marcmutz

src/corelib/thread/qtsan_impl.h

@@ -65,10 +65,10 @@ inline void mutexPostUnlock(void *addr, unsigned flags)
 }
 
 enum : unsigned {
-    ReadLock = ::__tsan_mutex_read_lock,
     MutexWriteReentrant = ::__tsan_mutex_write_reentrant,
     TryLock = ::__tsan_mutex_try_lock,
     TryLockFailed = ::__tsan_mutex_try_lock_failed,
+    ReadLock = ::__tsan_mutex_read_lock,
 };
 #else
 inline void futexAcquire(void *, void * = nullptr) {}
@@ -77,10 +77,10 @@ inline void latchCountDown(void *) {}
 inline void latchWait(const void *) {}
 
 enum : unsigned {
-    ReadLock,
     MutexWriteReentrant,
     TryLock,
     TryLockFailed,
+    ReadLock,
 };
 inline void mutexPreLock(void *, unsigned) {}
 inline void mutexPostLock(void *, unsigned, int) {}