Revert r312318, r312325, r312424, r312489

r312318 - Debug info for variables whose type is shrinked to bool
r312325, r312424, r312489 - Test case for r312318

Revision 312318 introduced a null dereference bug.
Details in https://bugs.llvm.org/show_bug.cgi?id=34490

llvm-svn: 312758