Allow integral Scalar to be extracted as bool

Summary:
In ATen, integral `Scalar`s are allowed to be extracted as `bool`. Example:

```
torch.ops.aten.add.out(torch.Tensor([0, 1]).to(dtype=torch.bool), torch.Tensor([1, 1]).to(dtype=torch.bool), alpha=4, out=torch.zeros(1).to(dtype=torch.bool))
```

This updates `extract_scalar` for the `bool` case to match this behaviour, where previously it would fail unless the `Scalar` was boolean.

Reviewed By: manuelcandales

Differential Revision: D46990102

fbshipit-source-id: 6d2875cfafbe2723cbf6855af55ded54c154e970

Author: SS-JIA

kernels/portable/cpu/scalar_utils.h

@@ -176,11 +176,15 @@ template <
     typename BOOL_T,
     std::enable_if_t<std::is_same_v<BOOL_T, bool>, bool> = true>
 bool extract_scalar(Scalar scalar, BOOL_T* out_val) {
-  if (!scalar.isBoolean()) {
-    return false;
+  if (scalar.isIntegral(false)) {
+    *out_val = static_cast<bool>(scalar.to<int64_t>());
+    return true;
   }
-  *out_val = scalar.to<bool>();
-  return true;
+  if (scalar.isBoolean()) {
+    *out_val = scalar.to<bool>();
+    return true;
+  }
+  return false;
 }
 
 } // namespace utils