patch 8.2.4993: smart/C/lisp indenting is optional

Problem:    smart/C/lisp indenting is optional, which makes the code more
            complex, while it only reduces the executable size a bit.
Solution:   Graduate FEAT_CINDENT, FEAT_SMARTINDENT and FEAT_LISP.

src/structs.h

@@ -2879,15 +2879,11 @@ struct file_buffer
     int		b_has_qf_entry;
 #endif
     int		b_p_bl;		// 'buflisted'
-#ifdef FEAT_CINDENT
     int		b_p_cin;	// 'cindent'
     char_u	*b_p_cino;	// 'cinoptions'
     char_u	*b_p_cink;	// 'cinkeys'
     char_u	*b_p_cinsd;	// 'cinscopedecls'
-#endif
-#if defined(FEAT_CINDENT) || defined(FEAT_SMARTINDENT)
     char_u	*b_p_cinw;	// 'cinwords'
-#endif
     char_u	*b_p_com;	// 'comments'
 #ifdef FEAT_FOLDING
     char_u	*b_p_cms;	// 'commentstring'
@@ -2926,7 +2922,7 @@ struct file_buffer
     long_u	b_p_inex_flags;	// flags for 'includeexpr'
 # endif
 #endif
-#if defined(FEAT_CINDENT) && defined(FEAT_EVAL)
+#if defined(FEAT_EVAL)
     char_u	*b_p_inde;	// 'indentexpr'
     long_u	b_p_inde_flags;	// flags for 'indentexpr'
     char_u	*b_p_indk;	// 'indentkeys'
@@ -2940,9 +2936,7 @@ struct file_buffer
     char_u	*b_p_key;	// 'key'
 #endif
     char_u	*b_p_kp;	// 'keywordprg'
-#ifdef FEAT_LISP
     int		b_p_lisp;	// 'lisp'
-#endif
     char_u	*b_p_menc;	// 'makeencoding'
     char_u	*b_p_mps;	// 'matchpairs'
     int		b_p_ml;		// 'modeline'
@@ -2956,9 +2950,7 @@ struct file_buffer
     int		b_p_ro;		// 'readonly'
     long	b_p_sw;		// 'shiftwidth'
     int		b_p_sn;		// 'shortname'
-#ifdef FEAT_SMARTINDENT
     int		b_p_si;		// 'smartindent'
-#endif
     long	b_p_sts;	// 'softtabstop'
     long	b_p_sts_nopaste; // b_p_sts saved for paste mode
 #ifdef FEAT_SEARCHPATH
@@ -3012,9 +3004,7 @@ struct file_buffer
 #ifdef FEAT_PERSISTENT_UNDO
     int		b_p_udf;	// 'undofile'
 #endif
-#ifdef FEAT_LISP
     char_u	*b_p_lw;	// 'lispwords' local value
-#endif
 #ifdef FEAT_TERMINAL
     long	b_p_twsl;	// 'termwinscroll'
 #endif
@@ -3023,7 +3013,6 @@ struct file_buffer
      * end of buffer options
      */
 
-#ifdef FEAT_CINDENT
     // values set from b_p_cino
     int		b_ind_level;
     int		b_ind_open_imag;
@@ -3062,7 +3051,6 @@ struct file_buffer
     int		b_ind_if_for_while;
     int		b_ind_cpp_extern_c;
     int		b_ind_pragma;
-#endif
 
     linenr_T	b_no_eol_lnum;	// non-zero lnum when last line of next binary
 				// write should not have an end-of-line