patch 8.1.1785: map functionality mixed with character input

Problem:    Map functionality mixed with character input.
Solution:   Move the map functionality to a separate file. (Yegappan
            Lakshmanan, closes #4740)  Graduate the +localmap feature.
diff --git a/src/structs.h b/src/structs.h
index 122e475..21b5f69 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -2293,13 +2293,12 @@
      */
     char_u	b_chartab[32];
 
-#ifdef FEAT_LOCALMAP
     // Table used for mappings local to a buffer.
     mapblock_T	*(b_maphash[256]);
 
     // First abbreviation local to a buffer.
     mapblock_T	*b_first_abbr;
-#endif
+
     // User commands local to the buffer.
     garray_T	b_ucmds;
     // start and end of an operator, also used for '[ and ']