no need for file-based registration as long as sought exe exists

Author: jonsequitur

src/System.CommandLine.Suggest/FileSuggestionRegistration.cs

@@ -43,14 +43,20 @@ public Registration FindRegistration(FileInfo soughtExecutable)
                 return null;
             }
 
+            if (soughtExecutable.Exists)
+            {
+                return new Registration(soughtExecutable.FullName);
+            }
+
             if (_registrationConfigurationFilePath == null
                 || !File.Exists(_registrationConfigurationFilePath))
             {
                 return null;
             }
 
-            string completionTarget = File.ReadAllLines(_registrationConfigurationFilePath).LastOrDefault(line =>
-                line.StartsWith(soughtExecutable.FullName, StringComparison.OrdinalIgnoreCase));
+            var completionTarget =
+                File.ReadAllLines(_registrationConfigurationFilePath).LastOrDefault(line =>
+                                                                                        line.StartsWith(soughtExecutable.FullName, StringComparison.OrdinalIgnoreCase));
 
             if (completionTarget == null)
             {