Remove ziplist dead code in object.c (redis#10751)

Remove some dead code in object.c, ziplist is no longer used in 7.0

Some backgrounds:
zipmap - hash: replaced by ziplist in redis#285
ziplist - hash: replaced by listpack in redis#8887
ziplist - zset: replaced by listpack in redis#9366
ziplist - list: replaced by quicklist (listpack) in redis#2143 / redis#9740

Moved the location of ziplist.h in the server.c

src/object.c

@@ -930,7 +930,6 @@ char *strEncoding(int encoding) {
     case OBJ_ENCODING_INT: return "int";
     case OBJ_ENCODING_HT: return "hashtable";
     case OBJ_ENCODING_QUICKLIST: return "quicklist";
-    case OBJ_ENCODING_ZIPLIST: return "ziplist";
     case OBJ_ENCODING_LISTPACK: return "listpack";
     case OBJ_ENCODING_INTSET: return "intset";
     case OBJ_ENCODING_SKIPLIST: return "skiplist";
@@ -998,8 +997,6 @@ size_t objectComputeSize(robj *key, robj *o, size_t sample_size, int dbid) {
                 samples++;
             } while ((node = node->next) && samples < sample_size);
             asize += (double)elesize/samples*ql->len;
-        } else if (o->encoding == OBJ_ENCODING_ZIPLIST) {
-            asize = sizeof(*o)+zmalloc_size(o->ptr);
         } else {
             serverPanic("Unknown list encoding");
         }

src/server.h

@@ -70,7 +70,6 @@ typedef long long ustime_t; /* microsecond time type. */
 #include "adlist.h"  /* Linked lists */
 #include "zmalloc.h" /* total memory usage aware version of malloc/free */
 #include "anet.h"    /* Networking the easy way */
-#include "ziplist.h" /* Compact list data structure */
 #include "intset.h"  /* Compact integer set structure */
 #include "version.h" /* Version macro */
 #include "util.h"    /* Misc functions useful in many places */
@@ -86,6 +85,7 @@ typedef long long ustime_t; /* microsecond time type. */
 
 /* Following includes allow test functions to be called from Redis main() */
 #include "zipmap.h"
+#include "ziplist.h" /* Compact list data structure */
 #include "sha1.h"
 #include "endianconv.h"
 #include "crc64.h"
@@ -828,9 +828,9 @@ typedef struct RedisModuleDigest {
 #define OBJ_ENCODING_RAW 0     /* Raw representation */
 #define OBJ_ENCODING_INT 1     /* Encoded as integer */
 #define OBJ_ENCODING_HT 2      /* Encoded as hash table */
-#define OBJ_ENCODING_ZIPMAP 3  /* Encoded as zipmap */
+#define OBJ_ENCODING_ZIPMAP 3  /* No longer used: old hash encoding. */
 #define OBJ_ENCODING_LINKEDLIST 4 /* No longer used: old list encoding. */
-#define OBJ_ENCODING_ZIPLIST 5 /* Encoded as ziplist */
+#define OBJ_ENCODING_ZIPLIST 5 /* No longer used: old list/hash/zset encoding. */
 #define OBJ_ENCODING_INTSET 6  /* Encoded as intset */
 #define OBJ_ENCODING_SKIPLIST 7  /* Encoded as skiplist */
 #define OBJ_ENCODING_EMBSTR 8  /* Embedded sds string encoding */