Go patch committed: Add missing Slice_info_expression::do_traverse

[Ian Lance Taylor via Gcc-patches]

This patch to the Go frontend adds the missing
Slice_info_expression::do_traverse method.  Lack of the method caused
https://go.dev/issue/59169.  The test case is
https://go.dev/cl/478217.  Bootstrapped and ran Go testsuite on
x86_64-pc-linux-gnu.  Committed to mainline and GCC 12 branch.

Ian

187edaf5e88b548db4e6790b723be1f8d1dab2d5
diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index 4a1a4c8c021..8c8025dec2e 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-8c786f716c58d7973623c2b9293e2ad360877817
+9ffd6e679ff0e3a908d0ec2ed5c6efa1de827c3f
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/gcc/go/gofrontend/expressions.h b/gcc/go/gofrontend/expressions.h
index a1e3733aa1d..3d7e78711bd 100644
--- a/gcc/go/gofrontend/expressions.h
+++ b/gcc/go/gofrontend/expressions.h
@@ -4410,6 +4410,10 @@ class Slice_info_expression : public Expression
   { return this->slice_info_; }
 
  protected:
+  int
+  do_traverse(Traverse* traverse)
+  { return Expression::traverse(&this->slice_, traverse); }
+
   Type*
   do_type();