Remove heap_hot_search().

After 71bdc99d0d, "tableam: Add helper for indexes to check if a
corresponding table tuples exist." there's no in-core user left. As
there's unlikely to be an external user, and such an external user
could easily be adjusted to use table_index_fetch_tuple_check(),
remove heap_hot_search().

Per complaint from Peter Geoghegan

Author: Andres Freund
Discussion: https://postgr.es/m/CAH2-Wzn0Oq4ftJrTqRAsWy2WGjv0QrJcwoZ+yqWsF_Z5vjUBFw@mail.gmail.com

src/backend/access/heap/heapam.c

@@ -1636,30 +1636,6 @@ heap_hot_search_buffer(ItemPointer tid, Relation relation, Buffer buffer,
 	return false;
 }
 
-/*
- *	heap_hot_search		- search HOT chain for tuple satisfying snapshot
- *
- * This has the same API as heap_hot_search_buffer, except that the caller
- * does not provide the buffer containing the page, rather we access it
- * locally.
- */
-bool
-heap_hot_search(ItemPointer tid, Relation relation, Snapshot snapshot,
-				bool *all_dead)
-{
-	bool		result;
-	Buffer		buffer;
-	HeapTupleData heapTuple;
-
-	buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
-	LockBuffer(buffer, BUFFER_LOCK_SHARE);
-	result = heap_hot_search_buffer(tid, relation, buffer, snapshot,
-									&heapTuple, all_dead, true);
-	LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
-	ReleaseBuffer(buffer);
-	return result;
-}
-
 /*
  *	heap_get_latest_tid -  get the latest tid of a specified tuple
  *

src/include/access/heapam.h

@@ -132,8 +132,6 @@ extern bool heap_fetch(Relation relation, Snapshot snapshot,
 extern bool heap_hot_search_buffer(ItemPointer tid, Relation relation,
 					   Buffer buffer, Snapshot snapshot, HeapTuple heapTuple,
 					   bool *all_dead, bool first_call);
-extern bool heap_hot_search(ItemPointer tid, Relation relation,
-				Snapshot snapshot, bool *all_dead);
 
 extern void heap_get_latest_tid(Relation relation, Snapshot snapshot,
 					ItemPointer tid);