internal/rosa: bison artifact

Required by dtc, which is required by qemu.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/gnu.go

@@ -23,6 +23,23 @@ chmod +w tests/test-c32ispunct.sh && echo '#!/bin/sh' > tests/test-c32ispunct.sh
 }
 func init() { artifactsF[M4] = Toolchain.newM4 }
 
+func (t Toolchain) newBison() pkg.Artifact {
+	const (
+		version  = "3.8.2"
+		checksum = "BhRM6K7URj1LNOkIDCFDctSErLS-Xo5d9ba9seg10o6ACrgC1uNhED7CQPgIY29Y"
+	)
+	return t.NewViaMake("bison", version, pkg.NewHTTPGetTar(
+		nil, "https://ftpmirror.gnu.org/gnu/bison/bison-"+version+".tar.gz",
+		mustDecode(checksum),
+		pkg.TarGzip,
+	), nil,
+		t.Load(M4),
+		t.Load(Diffutils),
+		t.Load(Sed),
+	)
+}
+func init() { artifactsF[Bison] = Toolchain.newBison }
+
 func (t Toolchain) newSed() pkg.Artifact {
 	const (
 		version  = "4.9"