patch 8.2.0864: pragmas are indented all the way to the left

Problem:    Pragmas are indented all the way to the left.
Solution:   Add an option to indent progmas like normal code. (Max Rumpf,
            closes #5468)

src/structs.h

@@ -2803,6 +2803,7 @@ struct file_buffer
     int		b_ind_cpp_namespace;
     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