Allocate enough memory in halide_malloc so that we can read a double beyond the end of the buffer. Update comments accordingly.
Allocate enough memory in halide_malloc so that we can read a double
beyond the end of the buffer. Update comments accordingly.


Former-commit-id: 828d670f92dc299ae16db435995ef05a708840c1
darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide