Set stack slot to null before calling destructor
Set stack slot to null before calling destructor

Just in case the destructor block gets branched to somehow.


Former-commit-id: 9ff4f3dc9d6b8de56f5a54f33f2c3eb6f989ec51
darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide