Add support for runtime arguments in injection points

The macros INJECTION_POINT() and INJECTION_POINT_CACHED() are extended
with an optional argument that can be passed down to the callback
attached when an injection point is run, giving to callbacks the
possibility to manipulate a stack state given by the caller.  The
existing callbacks in modules injection_points and test_aio have their
declarations adjusted based on that.

da7226993f (core AIO infrastructure) and 93bc3d75d8 (test_aio) and
been relying on a set of workarounds where a static variable called
pgaio_inj_cur_handle is used as runtime argument in the injection point
callbacks used by the AIO tests, in combination with a TRY/CATCH block
to reset the argument value.  The infrastructure introduced in this
commit will be reused for the AIO tests, simplifying them.

Reviewed-by: Greg Burd <greg@burd.me>
Discussion: https://postgr.es/m/Z_y9TtnXubvYAApS@paquier.xyz

src/backend/utils/cache/catcache.c

@@ -1926,7 +1926,7 @@ SearchCatCacheList(CatCache *cache,
 			/* Injection point to help testing the recursive invalidation case */
 			if (first_iter)
 			{
-				INJECTION_POINT("catcache-list-miss-systable-scan-started");
+				INJECTION_POINT("catcache-list-miss-systable-scan-started", NULL);
 				first_iter = false;
 			}
 

src/backend/utils/cache/inval.c

@@ -1207,7 +1207,7 @@ AtEOXact_Inval(bool isCommit)
 	/* Must be at top of stack */
 	Assert(transInvalInfo->my_level == 1 && transInvalInfo->parent == NULL);
 
-	INJECTION_POINT("transaction-end-process-inval");
+	INJECTION_POINT("transaction-end-process-inval", NULL);
 
 	if (isCommit)
 	{

src/backend/utils/cache/typcache.c

@@ -952,7 +952,7 @@ lookup_type_cache(Oid type_id, int flags)
 		load_domaintype_info(typentry);
 	}
 
-	INJECTION_POINT("typecache-before-rel-type-cache-insert");
+	INJECTION_POINT("typecache-before-rel-type-cache-insert", NULL);
 
 	Assert(in_progress_offset + 1 == in_progress_list_len);
 	in_progress_list_len--;