PR# 13560 Generated makefile clean and clobber directives do the wrong things

I believe I've reported the problem previously, but don't see it in my list of support issues.

When working in the w_code directory after a C compilation failure, I should be able to issue a command like

   nmake clean

and expect the intermediate libraries and whatnot to be deleted to force recompilation of the C code. It does not. Instead, if I go into one of the Cnn subdirectories, it runs the command:

        del core finished *.o

Maybe this would be useful on a Unix machine, but it's effectively a No-op on Windows. The LIB file is left intact and nothing will be rebuilt by running nmake.

Running it in the w_code directory itself results in a command that generates a syntax error:

        for i in C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 C17 \
   C18 C19 C20 C21 C22 C23 C24 C25 C26 C27 C28
   E1;  do  if [ -r $i\Makefile ]; then  (cd $i ; nmake -s -nologo clean); \
     fi;  done
   i was unexpected at this time.
   NMAKE : fatal error U1077: 'for' : return code '0x1'
   Stop.

This makes it tedious and error-prone to debug problems at the C level, since I can't reliably force recompilation of the C libraries in this way.