Arithmetic expansion bug.

[Isaac Marcos]

Description:

There is a bug when expanding this math:

    $ echo "$((~0))"
    bash: /home/user: syntax error: operand expected (error token is
"/home/user")

It works correctly when an space is added:

    $ echo "$(( ~0 ))"
    -1

Bash version:

    $ echo "$BASH_VERSION"
    4.4.12(1)-release





Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64'
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-pc-linux-gnu'
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL
-DHAVE_CONFIG_H   -I.  -I../. -I.././include -I.././lib  -Wdate-time
-D_FORTIFY_SOURCE=2 -g -O2 -fdebug-prefix-map=/build/bash-7fckc0/bash-4.4=.
-fstack-protector-strong -Wformat -Werror=format-security -Wall -no-pie
-Wno-parentheses -Wno-format-security
uname output: Linux IO.iafcg.priv 4.14.0-3-amd64 #1 SMP Debian 4.14.13-1
(2018-01-14) x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 4.4
Patch Level: 12
Release Status: release

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