Refactored Standard_ErrorHandler to use thread_local storage for the error handler stack
instead of a global list protected by mutex. This eliminates locking overhead entirely
since each thread only accesses its own error handlers.
Changes:
- Replaced global mutex-protected stack with thread_local Top pointer
- Simplified FindHandler() to directly return the thread-local Top
- Removed Catches() and LastCaughtError() methods (no longer needed)
- Added Raise() method for re-throwing caught exceptions
- Removed obsolete member variables: myStatus, myThread
- Deleted unused headers: Standard_HandlerStatus.hxx, Standard_JmpBuf.hxx, Standard_PErrorHandler.hxx
- Updated OCC_CATCH_SIGNALS macro to use new Raise() method
078dfc44ae