kill unused tinfo fields BCEflag/AMflag

src/lib/termdesc.c

@@ -390,13 +390,11 @@ int interrogate_terminfo(tinfo* ti, int fd, const char* termname, unsigned utf8,
     ti->escindices[ESCAPE_SMCUP] = 0;
     ti->escindices[ESCAPE_RMCUP] = 0;
   }
-  // check that the terminal provides automatic margins
-  ti->AMflag = tigetflag("am") == 1;
-  if(!ti->AMflag){
+  // ensure that the terminal provides automatic margins
+  if(tigetflag("am") != 1){
     fprintf(stderr, "Required terminfo capability 'am' not defined\n");
     goto err;
   }
-  ti->BCEflag = tigetflag("bce") == 1;
   if(get_escape(ti, ESCAPE_CIVIS) == NULL){
     char* chts;
     if(terminfostr(&chts, "chts") == 0){

src/lib/termdesc.h

@@ -143,8 +143,6 @@ typedef struct tinfo {
   struct termios tpreserved; // terminal state upon entry
   ncinputlayer input;       // input layer
   bool bitmap_supported;    // do we support bitmaps (post pixel_query_done)?
-  bool BCEflag;   // "BCE" flag for erases with background color
-  bool AMflag;    // "AM" flag for automatic movement to next line
 
   // mlterm resets the cursor (i.e. makes it visible) any time you print
   // a sprixel. we work around this spiritedly unorthodox decision. it