This feature was added to solve a lookup problem in expressions when local variables
shadow ivars. That solution requires fully realizing all local variables to evaluate
any expression, and can cause significant performance problems when evaluating
expressions in frames that have many complex locals.
Until we get a better solution, this setting mitigates the problem when you don't
have local variables that shadow ivars.
<rdar://problem/27226122>
llvm-svn: 274783