RFE: Add a %buildrequires section as an alternative to lots of BuildRequires: headers

[berolinux]

With rpm 4.20, we get %sourcelist and %patchlist to simplify the headers and make the spec file shorter and cleaner.
It would be equally useful, for the same reasons, to be able to replace

BuildRequires: pkgconfig(libxyz)
BuildRequires: pkgconfig(anotherlib) pkgconfig(yetanotherlib)
BuildRequires: cmake(andAnotherOne)
BuildRequires: whatever-devel >= 1.2-3

with the shorter

%buildrequires
pkgconfig(libxyz)
pkgconfig(anotherlib)
pkgconfig(yetanotherlib)
cmake(andAnotherOne)
whatever-devel >= 1.2-3

The same goes for runtime dependencies (but IMO that's less important, given most runtime dependencies are detected automatically anyway and they don't need huge lists in the spec).

[pmatilai]

Following this logic, we should support sections for all dependency types. It'd look very strange to have one for BuildRequires but not for eg Requires. Which is not to say it's a bad idea at all, and instead something we're slowly moving towards anyhow.

Note that %sourcelist and %patchlist are much older, they're in 4.15 already.

[ffesti]

The difference to %sourcelist and %patchlist is that dependencies can have flags. So we'd need some syntax for that.

[pmatilai]

Also, while the list format is handy in other ways, it kills grep'ability.