Problem: getchar() can't distinguish between C-I and Tab.
Solution: Add {opts} to pass extra flags to getchar() and getcharstr(),
with "number" and "simplify" keys.
related: #10603closes: #16554
Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>