repl: mkdir temp folder before chdir to avoid startup failure (#26805)

* repl: mkdir temp folder before chdir to avoid startup failure

When the REPL temp directory () does not exist,
called  before , so the
inside  was never reached and the REPL exited with:

  V repl error: Could not change the REPL working folder to ...': No such file or directory

Fix by calling  before  in .

Fixes #26804

* repl: error out if mkdir_all fails, per review feedback

---------

Co-authored-by: Richard Wheeler <18647491+PythonWillRule@users.noreply.github.com>

Author: quaesitor-scientiam

cmd/tools/vrepl.v

@@ -458,6 +458,10 @@ fn remove_comment(oline string) string {
 }
 
 fn run_repl(workdir string, vrepl_prefix string) int {
+	os.mkdir_all(workdir) or {
+		rerror('Could not create the REPL working folder `${workdir}`: ${err}')
+		return 1
+	}
 	os.chdir(workdir) or {
 		rerror('Could not change the REPL working folder to `${workdir}`: ${err}')
 		return 1