Make provides=(pkg) mean provides=(pkg=$pkgver) by default

Versioned dependencies are useless if the package providing them doesn't declare itself as provides=(PKG=VERSION) -- pacman doesn't know what version to read provides=(PKG) as implying and gives up immediately. However, in some cases this version is (apparently) easy to guess. For example, with variants of established packages, $pkgver is often the correct version to use (cf eg hledger extra/hledger,aur/hledger,aur/hledger-git). For VCS packages using the wiki-recommended pkgver=$basever.r$commitCount.g$hash, $basever appears to be the correct version. (cf eg pandoc aur/pandoc, aur/pandoc-crossref).

The one problem I can foresee is if eg the upstream project renamed and changed versioning schemes, so that a package might need to provides differing versions. However, in that case the version should be given explicitly anyway.

This has personally annoyed me in packaging aur/pandoc and aur/pandoc-crossref, but I let it slide as a personal issue. Now I have a user making such a request, I thought I'd raise the idea.f