REPLACE_xxx and USE_TOOLS+= xxx

[Frédéric Fauberteau <triaxx%netbsd.org@localhost>]

Hi folks,

I read in https://www.netbsd.org/docs/pkgsrc/fixes.html#shell-scripts:
> When using REPLACE_BASH, don't forget to add bash to USE_TOOLS.

Is there a reason why bash is not automatically added to USE_TOOLS if a REPLACE_BASH is declared?