Update on "[ExecuTorch] Dramatically improve op_clamp build time"

Instead of building `O(|CTYPE_IN| * |CTYPE_MIN| * |CTYPE_MAX| * |CTYPE_OUT|)` kernel code (where |T| means the number of possibilities for type T), we build `O((|CTYPE_IN| + |CTYPE_MIN| + |CTYPE_MAX| + |CTYPE_COMMON|) * |CTYPE_OUT|)` kernel code. (Concretely, `ET_SWITCH_REALHB_TYPES` has 9 possibilities, so I estimate that we went from 9**4 = 6561 template instantiations to 9 * 4 * 9 = 324
instantiations, or a 20x reduction.)


Differential Revision: [D63681034](https://our.internmc.facebook.com/intern/diff/D63681034/)

[ghstack-poisoned]

Author: swolchok

kernels/portable/cpu/util/broadcast_util.h

@@ -326,18 +326,16 @@ inline void apply_binary_elementwise_fn(
  * void(CTYPE_COMMON, void*), convert the given element to CTYPE_OUT,
  * and store it to the given location.
  */
-template <
-    typename CTYPE_COMMON,
-    typename Op>
+template <typename CTYPE_COMMON, typename Op>
 inline void apply_ternary_elementwise_fn(
     const Op& compute_fun,
     const Tensor& a,
     const Tensor& b,
     const Tensor& c,
     const Tensor& out,
-    CTYPE_COMMON(*load_a_to_common)(const void*),
-    CTYPE_COMMON(*load_b_to_common)(const void*),
-    CTYPE_COMMON(*load_c_to_common)(const void*),
+    CTYPE_COMMON (*load_a_to_common)(const void*),
+    CTYPE_COMMON (*load_b_to_common)(const void*),
+    CTYPE_COMMON (*load_c_to_common)(const void*),
     void (*store_common_to_out)(CTYPE_COMMON, void*)) {
   const bool a_is_broadcasted = !out.sizes().equals(a.sizes());
   const bool b_is_broadcasted = !out.sizes().equals(b.sizes());