Feat: allow downcasting (useful for certain cases where uint32_t needs

to be cast to float16_t because the bits are stored in the lower half of
the type)

Author: madhav-madhusoodanan

crates/intrinsic-test/src/x86/config.rs

@@ -329,7 +329,7 @@ pub const PLATFORM_C_FORWARD_DECLARATIONS: &str = r#"
         std::memcpy(&ret, &x, sizeof(T1));
         return ret;
       } else {
-        static_assert(sizeof(T1) == sizeof(T2) || std::is_convertible_v<T2, T1>,
+        static_assert(sizeof(T1) <= sizeof(T2) || std::is_convertible_v<T2, T1>,
                               "T2 must either be convertible to T1, or have the same size as T1!");
         return T1{};
       }