[analyzer] CStringChecker: Remember to highlight the argument expression range.
When emitting a bug report, it is important to highlight which argument of the
call-expression is causing the problem.
Before:
warning: Null pointer argument in call to string comparison function
strcmp(a, b);
^~~~~~~~~~~~
After:
warning: Null pointer argument in call to string comparison function
strcmp(a, b);
^ ~
Affects other output modes as well, not just text.
Differential Revision: https://reviews.llvm.org/D50028
llvm-svn: 338333