Retrieves the DRD-specific thread ID for the current thread context.
Executes the `DRD_GET_DRD_THREADID` client request to retrieve the thread ID
assigned by DRD to the current context.
The returned ID matches the thread IDs reported in DRD data race reports and
trace messages, making it useful for correlating log output with internal state.
# Mechanics
Unlike the core Valgrind thread IDs, DRD IDs have specific constraints:
- **1-based:** The first valid ID is 1.
- **Stable:** IDs are **never recycled**. When a thread exits, its ID is not
reused. This ensures the ID remains consistent throughout the execution log.
## Note
Requires Valgrind **3.3** or higher.