Fix DartDev run command failed reading Windows path

On Windows platform, backslashes are used as path separator. (Forward
slashes are also accepted by Windows APIs for most cases) But for an Uri
backslashes will be percent-encoded in the Uri. The other problem is
that "C:\directory" when passed into Uri, the drive letter will be
misinterpreted into scheme (common schemes like "http" or "file").

Bug: https://github.com/dart-lang/sdk/issues/42874
Change-Id: I0fe287b65a5b4faeb791665d2fda9ea0a9744cc4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/156363
Commit-Queue: Zichang Guo <zichangguo@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>

pkg/dartdev/lib/src/commands/run.dart

diff --git a/pkg/dartdev/lib/src/commands/run.dart b/pkg/dartdev/lib/src/commands/run.dart
index 86b7637..d118dbc 100644
--- a/pkg/dartdev/lib/src/commands/run.dart
+++ b/pkg/dartdev/lib/src/commands/run.dart
@@ -130,12 +130,9 @@
         return 255;
       }
     }
-
-    final script = Directory.current.uri
-        .resolve(args.firstWhere((e) => !e.startsWith('-')))
-        .toFilePath();
+    final path = args.firstWhere((e) => !e.startsWith('-'));
     final runArgs = args.length == 1 ? <String>[] : args.sublist(1);
-    VmInteropHandler.run(script, runArgs);
+    VmInteropHandler.run(path, runArgs);
     return 0;
   }
 }