[LLVM] Volunteer myself and Usman Nadeem as DFAJumpThreading maintainers (llvm#161491)

Both Usman Nadeem and I have constantly contributed to the
DFAJumpThreading pass so far. To push DFAJumpThreading forwards and make
it enabled by default, I volunteer myself and Usman Nadeem as
DFAJumpThreading maintainers.

Author: XChy

llvm/Maintainers.md

@@ -123,6 +123,13 @@ [email protected] (email), [alexey-bataev](https://github.com/alexey-bataev)
 Chandler Carruth \
 [email protected], [email protected] (email), [chandlerc](https://github.com/chandlerc) (GitHub)
 
+#### DFAJumpThreading
+
+Hongyu Chen \
+xxs\_[email protected] (email), [XChy](https://github.com/XChy) (Github) \
+Usman Nadeem \
+[email protected] (email), [UsmanNadeem](https://github.com/UsmanNadeem) (Github)
+
 ### Instrumentation and sanitizers
 
 #### Sanitizers not covered by someone else