bug#33197: 26.1; cc-mode enum indentation

["Ota, Takaaki" <Takaaki.Ota@sony.com>]

The enum indentation in cc-mode used to look like this.

	  enum {
	    pDlen = sizeof pD - 1,
	    pIlen = sizeof pI - 1,
	    pMlen = sizeof pMd - 2
	  };
	  enum {
	    no_modifier, long_modifier, pD_modifier, pI_modifier, pM_modifier
	  } length_modifier = no_modifier;

This is a portion of doprnt.c in the current 26.1 source code.  But
now the 26.1 cc-mode indents like this

	  enum {
                pDlen = sizeof pD - 1,
                pIlen = sizeof pI - 1,
                pMlen = sizeof pMd - 2
	  };
	  enum {
                no_modifier, long_modifier, pD_modifier, pI_modifier, pM_modifier
	  } length_modifier = no_modifier;

If the enum has a long name before the open brace it looks even worse
by wasting a lot of unnecessary spaces.

	  enum some_long_enum_type_name {
                                         pDlen = sizeof pD - 1,
                                         pIlen = sizeof pI - 1,
                                         pMlen = sizeof pMd - 2
	  };
	  enum another_long_enum_type_name {
                                            no_modifier, long_modifier, pD_modifier, pI_modifier, pM_modifier
	  } length_modifier = no_modifier;

Please consider bringing it back to how it used to be.

-Tak