Exclude expected completions for file: and line: args

We don't provide default argument completions for `#file` and `#line`,
for now let's avoid matching expected results if the argument list
contains `file:` and `line:`.

Author: hamishknight

SourceKitStressTester/Sources/StressTester/ActionGenerators.swift

@@ -528,7 +528,19 @@ private struct ActionToken {
         return nil
       }
     }
-    return expectedResultImpl(for: token, parent: parent)
+
+    let result = expectedResultImpl(for: token, parent: parent)
+
+    // If the argument labels are passing along `file` and `line` arguments,
+    // ignore this completion since we don't include `#file` and `#line` as
+    // completion args.
+    // FIXME: We ought to have this be configurable and enable it for the stress
+    // tester.
+    let argLabels = result.name.argLabels
+    if argLabels.contains("file") && argLabels.contains("line") {
+      return nil
+    }
+    return result
   }
 
   static func getParentArgs<T:SyntaxProtocol>(of syntax: T) -> (kind: ExpectedResult.Kind, args: [String])? {