46068 (tweaked) (was: github #57): region_highlight: Add memo= support.

This is useful when multiple plugins add region_highlight entries and
subsequently want to remove only their own entries.  Without this
functionality, recognizing one's region_highlight entries is not trivial
because the 'start' and 'end' offsets are modified by editing of $BUFFER
and the highlight specification may not be unique or distinctive.

The tweaks are as follows:

- Change zfree() to zsfree() per workers/46070.

- Remove the mem.c hunk, as it changed the signature of only one out of
  two alternative definitions of zsfree().  (The definition that hunk
  touched is the one that's not used by default.)

1 files changed, 4 insertions, 0 deletions

diff --git a/Src/Zle/zle.h b/Src/Zle/zle.h
index 609493f8c..391586c4a 100644
--- a/Src/Zle/zle.h
+++ b/Src/Zle/zle.h
@@ -447,6 +447,10 @@ struct region_highlight {
      * Any of the flags defined above.
      */
     int flags;
+    /*
+     * User-settable "memo" key.  Metafied.
+     */
+    const char *memo;
 };
 
 /*