Fix case for parent classes in autoload

Summary: The case of the name passed to autoload should match
the case in the extends/implements/use clause, not the
case of the class/interface/trait declaration.

Closes #3146

Reviewed By: @jdelong

Differential Revision: D1540544
Turn off ControlFlow by default in WholeProgram mode

Summary: Its no longer doing anything useful, and its 85% of the
postoptimize time. I'll turn it off first, and if no issues turn
up, I'll get rid of the code.

Reviewed By: @jdelong

Differential Revision: D1540059