LibJS: Convert to_u16() to ThrowCompletionOr

Author: https://github.com/IdanHo
Commit: 7bbb92dfe9
Pull-request: https://github.com/SerenityOS/serenity/pull/10522
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibJS/Runtime/ArrayBuffer.h

@@ -178,7 +178,7 @@ static ByteBuffer numeric_to_raw_bytes(GlobalObject& global_object, Value value,
             if constexpr (sizeof(UnderlyingBufferDataType) == 4)
                 int_value = MUST(value.to_u32(global_object));
             else if constexpr (sizeof(UnderlyingBufferDataType) == 2)
-                int_value = value.to_u16(global_object);
+                int_value = MUST(value.to_u16(global_object));
             else if constexpr (!IsSame<T, ClampedU8>)
                 int_value = value.to_u8(global_object);
             else