Remove CMARK_NODE__LAST_LINE_CHECKED flag

This flag was introduced by
#284, but we will not need it
once we update `S_ends_with_blank_line` to not use resursion in the next
commit.

src/blocks.c

@@ -36,10 +36,6 @@ static bool S_last_line_blank(const cmark_node *node) {
   return (node->flags & CMARK_NODE__LAST_LINE_BLANK) != 0;
 }
 
-static bool S_last_line_checked(const cmark_node *node) {
-  return (node->flags & CMARK_NODE__LAST_LINE_CHECKED) != 0;
-}
-
 static CMARK_INLINE cmark_node_type S_type(const cmark_node *node) {
   return (cmark_node_type)node->type;
 }
@@ -51,10 +47,6 @@ static void S_set_last_line_blank(cmark_node *node, bool is_blank) {
     node->flags &= ~CMARK_NODE__LAST_LINE_BLANK;
 }
 
-static void S_set_last_line_checked(cmark_node *node) {
-  node->flags |= CMARK_NODE__LAST_LINE_CHECKED;
-}
-
 static CMARK_INLINE bool S_is_line_end_char(char c) {
   return (c == '\n' || c == '\r');
 }
@@ -231,14 +223,10 @@ static void remove_trailing_blank_lines(cmark_strbuf *ln) {
 // Check to see if a node ends with a blank line, descending
 // if needed into lists and sublists.
 static bool S_ends_with_blank_line(cmark_node *node) {
-  if (S_last_line_checked(node)) {
-    return(S_last_line_blank(node));
-  } else if ((S_type(node) == CMARK_NODE_LIST ||
-              S_type(node) == CMARK_NODE_ITEM) && node->last_child) {
-    S_set_last_line_checked(node);
+  if ((S_type(node) == CMARK_NODE_LIST ||
+       S_type(node) == CMARK_NODE_ITEM) && node->last_child) {
     return(S_ends_with_blank_line(node->last_child));
   } else {
-    S_set_last_line_checked(node);
     return (S_last_line_blank(node));
   }
 }

src/node.h

@@ -49,7 +49,6 @@ typedef struct {
 enum cmark_node__internal_flags {
   CMARK_NODE__OPEN = (1 << 0),
   CMARK_NODE__LAST_LINE_BLANK = (1 << 1),
-  CMARK_NODE__LAST_LINE_CHECKED = (1 << 2),
 };
 
 struct cmark_node {