For inplace update, send nontransactional invalidations.

The inplace update survives ROLLBACK.  The inval didn't, so another
backend's DDL could then update the row without incorporating the
inplace update.  In the test this fixes, a mix of CREATE INDEX and ALTER
TABLE resulted in a table with an index, yet relhasindex=f.  That is a
source of index corruption.  Back-patch to v12 (all supported versions).
The back branch versions don't change WAL, because those branches just
added end-of-recovery SIResetAll().  All branches change the ABI of
extern function PrepareToInvalidateCacheTuple().  No PGXN extension
calls that, and there's no apparent use case in extensions.

Reviewed by Nitin Motiani and (in earlier versions) Andres Freund.

Discussion: https://postgr.es/m/20240523000548.58.nmisch@google.com

src/include/access/heapam_xlog.h

@@ -20,6 +20,7 @@
 #include "storage/buf.h"
 #include "storage/bufpage.h"
 #include "storage/relfilelocator.h"
+#include "storage/sinval.h"
 #include "utils/relcache.h"
 
 
@@ -425,9 +426,14 @@ typedef struct xl_heap_confirm
 typedef struct xl_heap_inplace
 {
 	OffsetNumber offnum;		/* updated tuple's offset on page */
+	Oid			dbId;			/* MyDatabaseId */
+	Oid			tsId;			/* MyDatabaseTableSpace */
+	bool		relcacheInitFileInval;	/* invalidate relcache init files */
+	int			nmsgs;			/* number of shared inval msgs */
+	SharedInvalidationMessage msgs[FLEXIBLE_ARRAY_MEMBER];
 } xl_heap_inplace;
 
-#define SizeOfHeapInplace	(offsetof(xl_heap_inplace, offnum) + sizeof(OffsetNumber))
+#define MinSizeOfHeapInplace	(offsetof(xl_heap_inplace, nmsgs) + sizeof(int))
 
 /*
  * This is what we need to know about setting a visibility map bit

src/include/access/xlog_internal.h

@@ -31,7 +31,7 @@
 /*
  * Each page of XLOG file has a header like this:
  */
-#define XLOG_PAGE_MAGIC 0xD117	/* can be used as WAL version indicator */
+#define XLOG_PAGE_MAGIC 0xD118	/* can be used as WAL version indicator */
 
 typedef struct XLogPageHeaderData
 {