Add recursive directory contents when using RunStep.addDirectoryArg and friends

[ikskuh]

zig/lib/std/Build/Step/Run.zig

Lines 643 to 648 in a931bfa

	.directory_source => |file| {
	const file_path = file.lazy_path.getPath2(b, step);
	try argv_list.append(b.fmt("{s}{s}", .{ file.prefix, file_path }));
	man.hash.addBytes(file.prefix);
	man.hash.addBytes(file_path);
	},

Right now, the directory path is cached, but not it's contents. This means when using a thing like

const bundle_step = b.addSystemCommand(&.{"tar", "-c"});

bundle_step.addArg("-f");
const asset_bundle_path = bundle_step.addOutputFileArg("result.tar");

bundle_step.addArg("-C");
bundle_step.addDirectoryArg(b.path("./assets"));

// asset_bundle_path is only generated once, no matter if the files inside ./assets ever change

[andrewrk]

I fixed this already in WriteFile step. Similar logic can be used.