internal/rosa/llvm: migrate runtimes and clang

This eliminates most newLLVM family of functions.

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

cmd/mbf/main.go

@@ -396,24 +396,27 @@ func main() {
 					rosa.SetGentooStage3(flagGentoo, checksum)
 				}
 
-				_, stage1 := (t - 2).NewLLVM()
-				_, stage2 := (t - 1).NewLLVM()
-				_, stage3 := t.NewLLVM()
 				var (
 					pathname *check.Absolute
 					checksum [2]unique.Handle[pkg.Checksum]
 				)
 
-				if pathname, _, err = cache.Cure(stage1); err != nil {
+				if pathname, _, err = cache.Cure(
+					(t - 2).Load(rosa.LLVMClang),
+				); err != nil {
 					return err
 				}
 				log.Println("stage1:", pathname)
 
-				if pathname, checksum[0], err = cache.Cure(stage2); err != nil {
+				if pathname, checksum[0], err = cache.Cure(
+					(t - 1).Load(rosa.LLVMClang),
+				); err != nil {
 					return err
 				}
 				log.Println("stage2:", pathname)
-				if pathname, checksum[1], err = cache.Cure(stage3); err != nil {
+				if pathname, checksum[1], err = cache.Cure(
+					t.Load(rosa.LLVMClang),
+				); err != nil {
 					return err
 				}
 				log.Println("stage3:", pathname)
@@ -565,7 +568,7 @@ func main() {
 			"shell",
 			"Interactive shell in the specified Rosa OS environment",
 			func(args []string) error {
-				presets := make([]rosa.PArtifact, len(args))
+				presets := make([]rosa.PArtifact, len(args)+3)
 				for i, arg := range args {
 					p, ok := rosa.ResolveName(arg)
 					if !ok {
@@ -573,25 +576,20 @@ func main() {
 					}
 					presets[i] = p
 				}
+
+				base := rosa.LLVMClang
+				if !flagWithToolchain {
+					base = rosa.Musl
+				}
+				presets = append(presets,
+					base,
+					rosa.Mksh,
+					rosa.Toybox,
+				)
+
 				root := make(pkg.Collect, 0, 6+len(args))
 				root = rosa.Std.AppendPresets(root, presets...)
 
-				if flagWithToolchain {
-					boot := rosa.Std - 1
-					runtimes, clang := boot.NewLLVM()
-					root = append(root,
-						boot.Load(rosa.Musl),
-						boot.Load(rosa.LLVMCompilerRT),
-						runtimes, clang,
-					)
-				} else {
-					root = append(root, rosa.Std.Load(rosa.Musl))
-				}
-				root = append(root,
-					rosa.Std.Load(rosa.Mksh),
-					rosa.Std.Load(rosa.Toybox),
-				)
-
 				if _, _, err := cache.Cure(&root); err == nil {
 					return errors.New("unreachable")
 				} else if !pkg.IsCollected(err) {