Update on "[Executorch] Add broadcasting support to optimized op_sub"

Summary:
This diff builds on top of previous one to add support for limited
handling of broadcasting for sub

Test Plan:
tests added

Reviewers:

Subscribers:

Tasks:

Tags:

cc larryliu0820 manuelcandales

Differential Revision: [D69491818](https://our.internmc.facebook.com/intern/diff/D69491818)

[ghstack-poisoned]

Author: kimishpatel

kernels/optimized/cpu/op_add_sub_impl.h

@@ -115,7 +115,6 @@ Tensor& opt_add_sub_out_impl(
   } else if (selected_optimized_path != ElementwiseOptimizedPath::kNone) {
     // Cannot apply the trick of -alpha here because alpha is Scalar without
     // support for - operator. At least not right now.
-    ScalarType out_type = out.scalar_type();
     ET_SWITCH_REALB_TYPES(out_type, ctx, op_name, CTYPE, [&]() {
       CTYPE alpha_val;
       ET_KERNEL_CHECK_MSG(

kernels/optimized/cpu/op_mul.cpp

@@ -130,7 +130,6 @@ Tensor& opt_mul_out(
           out.numel());
     });
   } else if (selected_optimized_path != ElementwiseOptimizedPath::kNone) {
-    ScalarType out_type = out.scalar_type();
     ET_SWITCH_REALB_TYPES(out_type, ctx, "mul.out", CTYPE, [&]() {
       auto mul_lambda = [](auto x, auto y) { return x * y; };
       return torch::executor::handle_broadcast_elementwise<CTYPE>(