test-command-template: rewrite recursion tests by using a map file

A literal template will be unnamed soon, so no recursion will be practically
made by using -T option.

tests/test-command-template.t

@@ -1180,7 +1180,10 b' Check that recursive reference does not '
 
  common mistake:
 
-  $ hg log -T '{changeset}\n'
+  $ cat << EOF > issue4758
+  > changeset = '{changeset}\n'
+  > EOF
+  $ hg log --style ./issue4758
   abort: recursive reference 'changeset' in template
   [255]
 
@@ -1196,7 +1199,10 b' Check that recursive reference does not '
 
  buildmap() -> gettemplate(), where no thunk was made:
 
-  $ hg log -T '{files % changeset}\n'
+  $ cat << EOF > issue4758
+  > changeset = '{files % changeset}\n'
+  > EOF
+  $ hg log --style ./issue4758
   abort: recursive reference 'changeset' in template
   [255]