Add correct typecasts for Loads in OpenCL C
Add correct typecasts for Loads in OpenCL C


Former-commit-id: 93bd85320d2fdbb8284e841371d796474a860c0e
darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide