Convert to new-style arrow switch.

PiperOrigin-RevId: 792533001
Change-Id: Id9bcb6fda32207c0a8f78ee6f1abd4b95c92ee94

Author: tjgq

src/main/java/com/google/devtools/build/lib/vfs/PathFragment.java

@@ -143,18 +143,15 @@ private static PathFragment createInternal(String path, OsPathPolicy osPathPolic
   }
 
   private static PathFragment makePathFragment(String normalizedPath, int driveStrLength) {
-    switch (driveStrLength) {
-      case 0:
-        return new RelativePathFragment(normalizedPath);
-      case 1:
-        return new UnixStyleAbsolutePathFragment(normalizedPath);
-      case 3:
-        return new WindowsStyleAbsolutePathFragment(normalizedPath);
-      default:
-        throw new IllegalStateException(
-            String.format(
-                "normalizedPath: %s, driveStrLength: %s", normalizedPath, driveStrLength));
-    }
+    return switch (driveStrLength) {
+      case 0 -> new RelativePathFragment(normalizedPath);
+      case 1 -> new UnixStyleAbsolutePathFragment(normalizedPath);
+      case 3 -> new WindowsStyleAbsolutePathFragment(normalizedPath);
+      default ->
+          throw new IllegalStateException(
+              String.format(
+                  "normalizedPath: %s, driveStrLength: %s", normalizedPath, driveStrLength));
+    };
   }
 
   /**