[COMMITTED] a68: add instructions on testing the ggc to README

[Jose E. Marchesi]

---
 gcc/algol68/README | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/gcc/algol68/README b/gcc/algol68/README
index 43515eaba85..9d1595ad8d8 100644
--- a/gcc/algol68/README
+++ b/gcc/algol68/README
@@ -93,6 +93,10 @@ Test in both 32-bit and 64-bit in multilib arches:
 
   $ make check-algol68 RUNTESTFLAGS="--target_board=unix\{-m64,-m32\}"
 
+Test that integration with the GCC GC is correct:
+
+  $ make check-algol68 RUNTESTFLAGS="CFLAGS_FOR_TARGET='--param=ggc-min-expand=0 --param=ggc-min-heapsize=0'"
+
 Logs (with corresponding commands) can be found in
 BUILD/gcc/testsuite/algol68/algol68.log.
 
-- 
2.30.2