Auto merge of #54517 - mcr431:53956-panic-on-include_bytes-of-own-file, r=michaelwoerister

53956 panic on include bytes of own file

fix #53956

When using `include_bytes!` on a source file in the project, compiler would panic on subsequent compilations because `expand_include_bytes` would overwrite files in the source_map with no source. This PR changes `expand_include_bytes` to check source_map and use the already existing src, if any.

src/libsyntax/parse/lexer/mod.rs

@@ -1900,7 +1900,7 @@ mod tests {
                  sess: &'a ParseSess,
                  teststr: String)
                  -> StringReader<'a> {
-        let sf = sm.new_source_file(PathBuf::from("zebra.rs").into(), teststr);
+        let sf = sm.new_source_file(PathBuf::from(teststr.clone()).into(), teststr);
         StringReader::new(sess, sf, None)
     }