internal/rosa/llvm: autodetect stage0 target

This is fine, now that stages beyond stage0 have explicit target.

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

internal/rosa/llvm.go

@@ -1,10 +1,6 @@
 package rosa
 
-import (
-	"runtime"
-
-	"hakurei.app/internal/pkg"
-)
+import "hakurei.app/internal/pkg"
 
 func init() {
 	artifactsM[llvmSource] = Metadata{
@@ -146,17 +142,7 @@ func init() {
 func (t Toolchain) newClang() (pkg.Artifact, string) {
 	target := "'AArch64;RISCV;X86'"
 	if t.isStage0() {
-		switch runtime.GOARCH {
-		case "386", "amd64":
-			target = "X86"
-		case "arm64":
-			target = "AArch64"
-		case "riscv64":
-			target = "RISCV"
-
-		default:
-			panic("unsupported target " + runtime.GOARCH)
-		}
+		target = "Native"
 	}
 
 	return t.NewPackage("clang", llvmVersion, t.Load(llvmSource), &PackageAttr{