bug#11475: 24.0.96; Crash in compact_small_strings

[Chong Yidong]

> #1  0x0114f346 in w32_abort () at w32fns.c:7210
>         button = 6
> #2  0x0103ac41 in compact_small_strings () at alloc.c:2272
>         nbytes = 1702196083
>         b = 0x6f80000
>         tb = 0x6f23000
>         next = 0x83f5f8
>         from = 0x6f81e08
>         to = 0x6f23ae0
>         end = 0x6f81ffc
>         tb_end = 0x6f24ffc
>         to_end = 0x6f23ae0
>         from_end = 0x6f81e08
> #3  0x0103ab4b in sweep_strings () at alloc.c:2197
>         b = 0x0
>         next = 0x0
>         live_blocks = 0x563c400

Please do

f 2
p *from