cmd: Added some expansion tests.

programs/cmd/tests/test_builtins.cmd

@@ -23,6 +23,21 @@ cd dummydir
 echo %~dp0
 cd ..
 rmdir dummydir
+echo %CD%
+echo %%
+echo P%
+echo %P
+echo %UNKNOWN%S
+echo P%UNKNOWN%
+echo P%UNKNOWN%S
+echo %ERRORLEVEL
+echo %ERRORLEVEL%
+echo %ERRORLEVEL%%ERRORLEVEL%
+echo %ERRORLEVEL%%
+echo %ERRORLEVEL%%%
+echo P%ERRORLEVEL%
+echo %ERRORLEVEL%S
+echo P%ERRORLEVEL%S
 
 echo ------------ Testing if/else --------------
 echo if/else should work with blocks

programs/cmd/tests/test_builtins.cmd.exp

@@ -16,6 +16,21 @@ bar
 ~dp0 should be directory containing batch file
 @pwd@\
 @pwd@\
+@pwd@
+%
+P
+P
+S
+P
+PS
+ERRORLEVEL
+0
+00
+0
+0%
+P0
+0S
+P0S
 ------------ Testing if/else --------------
 if/else should work with blocks
 if seems to work