ast: fix check-condition failure in This.resolveTypes

fixes #3371

src/dev/flang/ast/This.java

@@ -242,7 +242,7 @@ else if (f.isUniverse())
          */
         var cur = _cur == null ? outer : _cur;
         getOuter = new Current(pos(), cur);
-        while (f != Types.f_ERROR && cur != f)
+        while (f != Types.f_ERROR && cur != f && !cur.isUniverse())
           {
             var or = cur.outerRef();
             if (CHECKS) check

tests/reg_issue3371/Makefile

@@ -0,0 +1,25 @@
+# This file is part of the Fuzion language implementation.
+#
+# The Fuzion language implementation is free software: you can redistribute it
+# and/or modify it under the terms of the GNU General Public License as published
+# by the Free Software Foundation, version 3 of the License.
+#
+# The Fuzion language implementation is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License along with The
+# Fuzion language implementation.  If not, see <https://www.gnu.org/licenses/>.
+
+
+# -----------------------------------------------------------------------
+#
+#  Tokiwa Software GmbH, Germany
+#
+#  Source code of Fuzion test Makefile
+#
+# -----------------------------------------------------------------------
+
+override NAME = reg_issue3371
+include ../simple.mk

tests/reg_issue3371/reg_issue3371.fz

@@ -0,0 +1,27 @@
+# This file is part of the Fuzion language implementation.
+#
+# The Fuzion language implementation is free software: you can redistribute it
+# and/or modify it under the terms of the GNU General Public License as published
+# by the Free Software Foundation, version 3 of the License.
+#
+# The Fuzion language implementation is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License along with The
+# Fuzion language implementation.  If not, see <https://www.gnu.org/licenses/>.
+
+
+# -----------------------------------------------------------------------
+#
+#  Tokiwa Software GmbH, Germany
+#
+#  Source code of Fuzion test
+#
+# -----------------------------------------------------------------------
+
+a := [("Alice", 23), ("Bob", 12), ("Charly", 32)]
+age_sum := a.map (p -> p.1) |> sum
+count   := a.map (p -> 1) |> sum
+say "average age {age_sum / count}"

tests/reg_issue3371/reg_issue3371.fz.expected_out

@@ -0,0 +1 @@
+average age 22