This reverts commit 5202072a.

Fix false positive for SC2312 when using `time`

Support more Bash internal variables

Suppress SC2311 with `set -o posix`

Add `mapfile` to harmless commands for SC2094

  - BASH_ARGV0, introduced in Bash 5.0
  - BASH_COMPAT, 4.3
  - BASH_LOADABLES_PATH, 4.4
  - CHILD_MAX, 4.3
  - EPOCHREALTIME, 5.0
  - EPOCHSECONDS, 5.0
  - EXECIGNORE, 4.4
  - INSIDE_EMACS, 4.4
  - PS0, 4.4
  - READLINE_ARGUMENT, 5.2
  - READLINE_MARK, 5.1
  - SRANDOM, 5.1

Fixes #1780 and #2554.

No functional changes; this just makes the next few commits cleaner.

This fixes `Prelude.foldl1: empty list []` when script has `( exit )`

Merge branch 'grammer_fix_sc2183' of https://github.com/ygeyzel/shellcheck into ygeyzel-grammer_fix_sc2183

Add escape characters to SC2028: \a, \b, \e, \f, \v, \\, \', \OOO, \xHH