Back-patch log_newpage_range().

Back-patch a subset of commit 9155580fd5
to v11, v10, 9.6, and 9.5.  Include the latest repairs to this function.
Use a new XLOG_FPI_MULTI value instead of reusing XLOG_FPI.  That way,
if an older server reads WAL from this function, that server will PANIC
instead of applying just one page of the record.  The next commit adds a
call to this function.

Discussion: https://postgr.es/m/20200304.162919.898938381201316571.horikyota.ntt@gmail.com

src/include/access/xloginsert.h

@@ -16,6 +16,7 @@
 #include "storage/block.h"
 #include "storage/buf.h"
 #include "storage/relfilenode.h"
+#include "utils/relcache.h"
 
 /*
  * The minimum size of the WAL construction working area. If you need to
@@ -54,6 +55,8 @@ extern bool XLogCheckBufferNeedsBackup(Buffer buffer);
 extern XLogRecPtr log_newpage(RelFileNode *rnode, ForkNumber forkNum,
 			BlockNumber blk, char *page, bool page_std);
 extern XLogRecPtr log_newpage_buffer(Buffer buffer, bool page_std);
+extern void log_newpage_range(Relation rel, ForkNumber forkNum,
+				  BlockNumber startblk, BlockNumber endblk, bool page_std);
 extern XLogRecPtr XLogSaveBufferForHint(Buffer buffer, bool buffer_std);
 
 extern void InitXLogInsert(void);