Fix #15055

Author: mbovel

compiler/src/dotty/tools/io/VirtualFile.scala

@@ -6,7 +6,7 @@
 package dotty.tools.io
 
 import scala.language.unsafeNulls
-
+import java.nio.file.Paths
 import java.io.{ ByteArrayInputStream, ByteArrayOutputStream, InputStream, OutputStream }
 
 /** This class implements an in-memory file.
@@ -36,7 +36,7 @@ class VirtualFile(val name: String, override val path: String) extends AbstractF
     * @return     the created virtual file
     */
   def this(path: String, content: Array[Byte]) = {
-    this(VirtualFile.nameOf(path), path)
+    this(Paths.get(path).getFileName().toString(), path)
     this.content = content
   }
 
@@ -104,7 +104,3 @@ class VirtualFile(val name: String, override val path: String) extends AbstractF
    */
   def lookupNameUnchecked(name: String, directory: Boolean): AbstractFile = unsupported()
 }
-object VirtualFile:
-  private def nameOf(path: String): String =
-    val i = path.lastIndexOf('/')
-    if i >= 0 && i < path.length - 1 then path.substring(i + 1) else path