Fixed stack clobbering of def/min/max.
Fixed stack clobbering of def/min/max.


Former-commit-id: 6461afda074c6c760899226883f14c602dd9b8b0
darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide