Add test to check implicit upcasting of float16_t works.
Add test to check implicit upcasting of float16_t works.


Former-commit-id: 4516e4579445ff475b4e040b0c9834e86b14c1eb
Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide