internal/rosa/gnu: skip libtool tests in stage0

This upsets the linker in stage0.

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

internal/rosa/gnu.go

@@ -186,6 +186,9 @@ func (t Toolchain) newLibtool() (pkg.Artifact, string) {
 		checksum,
 		pkg.TarGzip,
 	), nil, &MakeHelper{
+		// _Z2a2c: symbol not found
+		SkipCheck: t.isStage0(),
+
 		Check: []string{
 			"TESTSUITEFLAGS=" + jobsFlagE,
 			"check",