The change is based on:

commit 190c644c06369766aa2537851ddbf83b1231b65b
Author: Philipp Fent <fent@in.tum.de>
Date:   Sun Sep 4 20:47:34 2022 +0200

    libstdc++: Fix pretty printer tests of tuple indexes

but it is adapted to GCC8 since it does not have the tuple inheritance change,
which is:

commit 91e6226f880b048275a7ceedef716e159c7cefd9
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Aug 7 17:13:56 2020 +0100

    libstdc++: Remove inheritance from elements in std::tuple

diff --git a/libstdc++-v3/testsuite/libstdc++-prettyprinters/48362.cc b/libstdc++-v3/testsuite/libstdc++-prettyprinters/48362.cc
index cc91803e247..af335d0d3c7 100644
--- a/libstdc++-v3/testsuite/libstdc++-prettyprinters/48362.cc
+++ b/libstdc++-v3/testsuite/libstdc++-prettyprinters/48362.cc
@@ -29,7 +29,7 @@ main()
 // { dg-final { note-test t1 {empty std::tuple} } }
 
   std::tuple<std::string, int, std::tuple<>> t2{ "Johnny", 5, {} };
-// { dg-final { regexp-test t2 {std::tuple containing = {\[1\] = "Johnny", \[2\] = 5, \[3\] = {<std::(__8::)?tuple<>> = empty std::tuple, <No data fields>}}} } }
+// { dg-final { regexp-test t2 {std::tuple containing = {\[0\] = "Johnny", \[1\] = 5, \[2\] = {<std::(__8::)?tuple<>> = empty std::tuple, <No data fields>}}} } }
 
   std::cout << "\n";
   return 0; // Mark SPOT