Vectorized calls to externs work again.
Vectorized calls to externs work again.


Former-commit-id: 6f62a9ca182179291ded55b1a7f0071f874cef6e
darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide