Reached unreachable code in digitToChar function.

[KeithBrown39423]

Zig Version

0.13.0

Steps to Reproduce and Observed Behavior

To reproduce this, call the std.fmt.digitToChar function with a value that is higher than 36.

Example code

const std = @import("std");

pub fn main() !void {
    const c = std.fmt.digitToChar(89, .upper);
    std.debug.print("{}", .{c});
}

thread 5932 panic: reached unreachable code
C:\Users\keith\.zvm\0.13.0\lib\std\fmt.zig:1766:17: 0x3c10dd in digitToChar (zig-testing.exe.obj)
        else => unreachable,
                ^
C:\Users\keith\OneDrive\Documents\projects\zig-testing\src\main.zig:4:34: 0x3c1018 in main (zig-testing.exe.obj)
    const c = std.fmt.digitToChar(89, .upper);
                                 ^
C:\Users\keith\.zvm\0.13.0\lib\std\start.zig:363:53: 0x3c1391 in WinStartup (zig-testing.exe.obj)
    std.os.windows.ntdll.RtlExitUserProcess(callMain());
                                                    ^
???:?:?: 0x7ffbb544e8d6 in ??? (KERNEL32.DLL)
???:?:?: 0x7ffbb63ffbcb in ??? (ntdll.dll)

Expected Behavior

Technically, this works as expected, but in reality it should return an invalid parameter error.