support: internal/oserror, io, io/fs

cl/import.go

@@ -531,7 +531,7 @@ func ignoreName(name string) bool {
 
 func supportedInternal(name string) bool {
 	return strings.HasPrefix(name, "abi.") || strings.HasPrefix(name, "bytealg.") ||
-		strings.HasPrefix(name, "reflectlite.")
+		strings.HasPrefix(name, "oserror.") || strings.HasPrefix(name, "reflectlite.")
 }
 
 // -----------------------------------------------------------------------------

internal/build/build.go

@@ -664,6 +664,8 @@ func canSkipToBuild(pkgPath string) bool {
 	switch pkgPath {
 	case "unsafe":
 		return true
+	case "internal/oserror":
+		return false
 	default:
 		return strings.HasPrefix(pkgPath, "internal/") ||
 			strings.HasPrefix(pkgPath, "runtime/internal/")
@@ -678,8 +680,8 @@ var hasAltPkg = map[string]none{
 	"internal/abi":         {},
 	"internal/bytealg":     {},
 	"internal/reflectlite": {},
-	"io":                   {},
+	//"io":                 {},
-	"io/fs":                {},
+	//"io/fs":              {},
 	"math":        {},
 	"math/cmplx":  {},
 	"reflect":     {},