internal/rosa: improve cmake interface

This should make the call site look better for new artifacts.

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

internal/rosa/llvm.go

@@ -180,18 +180,6 @@ cp -r /system/include /usr/include && rm -rf /system/include
 	), &CMakeAttr{
 		Cache:  slices.Concat(cache, attr.cmake),
 		Append: cmakeAppend,
-		Extra: stage3Concat(t, attr.extra,
-			t.Load(Libffi),
-			t.Load(Python),
-			t.Load(Perl),
-			t.Load(Diffutils),
-			t.Load(Bash),
-			t.Load(Gawk),
-			t.Load(Coreutils),
-			t.Load(Findutils),
-
-			t.Load(KernelHeaders),
-		),
 		Prefix: attr.prefix,
 
 		Env: slices.Concat([]string{
@@ -200,8 +188,19 @@ cp -r /system/include /usr/include && rm -rf /system/include
 		}, attr.env),
 		ScriptEarly: scriptEarly, Script: script + attr.script,
 
-		Exclusive: true,
-	})
+		Flag: TExclusive,
+	}, stage3Concat(t, attr.extra,
+		t.Load(Libffi),
+		t.Load(Python),
+		t.Load(Perl),
+		t.Load(Diffutils),
+		t.Load(Bash),
+		t.Load(Gawk),
+		t.Load(Coreutils),
+		t.Load(Findutils),
+
+		t.Load(KernelHeaders),
+	)...)
 }
 
 // newLLVM returns LLVM toolchain across multiple [pkg.Artifact].