runtime(sh): refactored sh.vim syntax script

- unified bashStatement, kshStatement and shStatement as much as
  possible
- separated builtin commands from external programs
- cleaned up kornshell flavor logic
- fixed alias syntax highlighting
- added test for bash alias syntax highlighting
- removed daemon keyword

closes: #18355

Signed-off-by: Bjoern Foersterling <bjoern.foersterling@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/syntax/testdir/input/sh_09.sh

@@ -16,4 +16,5 @@
 ( cd ${HOME} ; $pwd ) | wc -c
 ( cd ${HOME} ) | wc -c
 ((n=1+2))
+# this is a syntax error, "let" is not a keyword in dash
 let n=1+2

runtime/syntax/testdir/input/sh_bash_alias.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/bash
+
+alias ls='ls --color=auto'

runtime/syntax/testdir/input/sh_ksh2020.ksh

@@ -88,7 +88,7 @@ poll --man
 # mkservice and eloop (rarely provided; requires SHOPT_MKSERVICE)
 mkservice --man; eloop --help
 
-# some mksh builtins
+# some mksh builtins, rename should be highlighted as external program
 bind; rename
 
 # ;& and ;;& in case statements

runtime/syntax/testdir/input/sh_ksh88.ksh

@@ -88,7 +88,7 @@ poll --man
 # mkservice and eloop (rarely provided; requires SHOPT_MKSERVICE)
 mkservice --man; eloop --help
 
-# some mksh builtins
+# some mksh builtins, rename should be highlighted as external program
 bind; rename
 
 # ;& and ;;& in case statements

runtime/syntax/testdir/input/sh_ksh93u.ksh

@@ -88,7 +88,7 @@ poll --man
 # mkservice and eloop (rarely provided; requires SHOPT_MKSERVICE)
 mkservice --man; eloop --help
 
-# some mksh builtins
+# some mksh builtins, rename should be highlighted as external command
 bind; rename
 
 # ;& and ;;& in case statements

runtime/syntax/testdir/input/sh_ksh93v.ksh

@@ -88,7 +88,7 @@ poll --man
 # mkservice and eloop (rarely provided; requires SHOPT_MKSERVICE)
 mkservice --man; eloop --help
 
-# some mksh builtins
+# some mksh builtins, rename should be highlighted as external program
 bind; rename
 
 # ;& and ;;& in case statements

runtime/syntax/testdir/input/sh_sundrous.bash

@@ -54,4 +54,5 @@ uname
 uniq
 wc
 xargs
+# xgrep is neither a builtin for bash nor an external program
 xgrep