Fix pg_size_bytes() to be more portable.

Commit 53874c52 broke various 32-bit
buildfarm machines because it incorrectly used an 'L' suffix for what
needed to be a 64-bit literal. Thanks to Michael Paquier for helping
to diagnose this.

src/backend/utils/adt/dbsize.c

@@ -821,7 +821,7 @@ pg_size_bytes(PG_FUNCTION_ARGS)
 		else if (pg_strcasecmp(strptr, "gb") == 0)
 			multiplier = 1024 * 1024 * 1024;
 		else if (pg_strcasecmp(strptr, "tb") == 0)
-			multiplier = 1024 * 1024 * 1024 * 1024L;
+			multiplier = 1024 * 1024 * 1024 * 1024LL;
 		else
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),