Fix gendered documentation

Changed two references to developers as "he" or "him" to the more neutral "they".

Reviewed By: JDevlieghere, sylvestre.ledru

Differential Revision: https://reviews.llvm.org/D78807

clang-tools-extra/docs/clang-tidy/checks/google-objc-global-variable-declaration.rst

@@ -44,4 +44,4 @@ However for code that prefixed with non-alphabetical characters like:
   static NSString* __anotherString = @"world";
 
 The check will give a warning message but will not be able to suggest a fix. The
-user need to fix it on his own.
+user needs to fix it on their own.

lldb/docs/use/variable.rst

@@ -993,7 +993,7 @@ have many member variables but not all of these are actually necessary for the
 user to see.
 
 A filter will solve this issue by only letting the user see those member
-variables he cares about. Of course, the equivalent of a filter can be
+variables they care about. Of course, the equivalent of a filter can be
 implemented easily using synthetic children, but a filter lets you get the job
 done without having to write Python code.