Fix a bug with C code gen of code using memoize_expr where compilation would incorrectly assert if multiple exprs were added to the cache tag.
Fix a bug with C code gen of code using memoize_expr where compilation
would incorrectly assert if multiple exprs were added to the cache tag.


Former-commit-id: d5697d9d6f5cf993f58e126d7acc355a2c3296c4
Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide