XLogRegisterData, XLogRegisterBufData void * argument for binary data

Change XLogRegisterData() and XLogRegisterBufData() functions to take
void * for binary data instead of char *.  This will remove the need
for numerous casts (done in a separate commit for clarity).

Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Discussion: https://www.postgresql.org/message-id/flat/fd1fcedb-3492-4fc8-9e3e-74b97f2db6c7%40eisentraut.org

src/backend/access/transam/README

@@ -586,13 +586,13 @@ void XLogRegisterBuffer(uint8 block_id, Buffer buf, uint8 flags);
     XLogRegisterBufData() is included in the WAL record even if a full-page
     image is taken.
 
-void XLogRegisterData(const char *data, int len);
+void XLogRegisterData(const void *data, int len);
 
     XLogRegisterData is used to include arbitrary data in the WAL record.  If
     XLogRegisterData() is called multiple times, the data are appended, and
     will be made available to the redo routine as one contiguous chunk.
 
-void XLogRegisterBufData(uint8 block_id, const char *data, int len);
+void XLogRegisterBufData(uint8 block_id, const void *data, int len);
 
     XLogRegisterBufData is used to include data associated with a particular
     buffer that was registered earlier with XLogRegisterBuffer().  If

src/backend/access/transam/xloginsert.c

@@ -361,7 +361,7 @@ XLogRegisterBlock(uint8 block_id, RelFileLocator *rlocator, ForkNumber forknum,
  * XLogRecGetData().
  */
 void
-XLogRegisterData(const char *data, uint32 len)
+XLogRegisterData(const void *data, uint32 len)
 {
 	XLogRecData *rdata;
 
@@ -402,7 +402,7 @@ XLogRegisterData(const char *data, uint32 len)
  * limited)
  */
 void
-XLogRegisterBufData(uint8 block_id, const char *data, uint32 len)
+XLogRegisterBufData(uint8 block_id, const void *data, uint32 len)
 {
 	registered_buffer *regbuf;
 	XLogRecData *rdata;

src/include/access/xlog_internal.h

@@ -312,7 +312,7 @@ typedef struct xl_end_of_recovery
 typedef struct XLogRecData
 {
 	struct XLogRecData *next;	/* next struct in chain, or NULL */
-	const char *data;			/* start of rmgr data to include */
+	const void *data;			/* start of rmgr data to include */
 	uint32		len;			/* length of rmgr data to include */
 } XLogRecData;
 

src/include/access/xloginsert.h

@@ -45,12 +45,12 @@ extern void XLogBeginInsert(void);
 extern void XLogSetRecordFlags(uint8 flags);
 extern XLogRecPtr XLogInsert(RmgrId rmid, uint8 info);
 extern void XLogEnsureRecordSpace(int max_block_id, int ndatas);
-extern void XLogRegisterData(const char *data, uint32 len);
+extern void XLogRegisterData(const void *data, uint32 len);
 extern void XLogRegisterBuffer(uint8 block_id, Buffer buffer, uint8 flags);
 extern void XLogRegisterBlock(uint8 block_id, RelFileLocator *rlocator,
 							  ForkNumber forknum, BlockNumber blknum, const PageData *page,
 							  uint8 flags);
-extern void XLogRegisterBufData(uint8 block_id, const char *data, uint32 len);
+extern void XLogRegisterBufData(uint8 block_id, const void *data, uint32 len);
 extern void XLogResetInsertion(void);
 extern bool XLogCheckBufferNeedsBackup(Buffer buffer);