Should debuginfo special-case vectors?

[scottmcm]

In #129403 I'm seeing that using array-based SIMD types changes the debug info you get from them, and thus #128866 has in fact already changed the debuginfo you get from platform types like __m256.

 // gdb-command:print vi8x16
-// gdb-check:$1 = simd::i8x16 (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
+// gdb-check:$1 = simd::i8x16 ([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15])

Should debug-info notice the Vector ABI and emit something that doesn't get double-braced? Or does it not matter and the ([1, 2]) is completely fine so it's not worth changing?