Go: Exclude dummy files from File

Author: mbg

go/ql/lib/semmle/go/Files.qll

@@ -124,6 +124,7 @@ class ExtractedOrExternalFile extends Container, Impl::File, Documentable, ExprP
 /** A file that has been extracted. */
 class File extends ExtractedOrExternalFile {
   File() {
+    not this.getBaseName() = "-" and
     // getAChild is specifically for the Go AST and so does not apply to non-go files
     // we care about all non-go extracted files, as only go files can have `@file` entries due to requiring a file entry for diagnostic errors
     not this.getExtension() = "go"