'main': Prepare to add additional fields to $precommand_options values.
'main': Prepare to add additional fields to $precommand_options values.

No functional change.

P71/zsh-syntax-highlighting,phy1729/zsh-syntax-highlighting,zsh-users/zsh-syntax-highlighting,phy1729/zsh-syntax-highlighting,zsh-users/zsh-syntax-highlighting,P71/zsh-syntax-highlighting