Stop requiring function_argzero

This commit is based on [zsh-syntax-highlighting's similar commit][1].

Also, motivated from PR #640.

[1]: https://github.com/zsh-users/zsh-syntax-highlighting/commit/750aebc553f2f4149055ef4cb9d7641f5df6d3ea

src/config.zsh

@@ -28,6 +28,8 @@ typeset -g ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX=autosuggest-orig-
 		history-search-backward
 		history-beginning-search-forward
 		history-beginning-search-backward
+		history-beginning-search-forward-end
+		history-beginning-search-backward-end
 		history-substring-search-up
 		history-substring-search-down
 		up-line-or-beginning-search

zsh-autosuggestions.plugin.zsh

@@ -1 +1,2 @@
+0=${(%):-%N}
 source ${0:A:h}/zsh-autosuggestions.zsh

zsh-autosuggestions.zsh

@@ -54,6 +54,8 @@ typeset -g ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX=autosuggest-orig-
 		history-search-backward
 		history-beginning-search-forward
 		history-beginning-search-backward
+		history-beginning-search-forward-end
+		history-beginning-search-backward-end
 		history-substring-search-up
 		history-substring-search-down
 		up-line-or-beginning-search