Run Ruby 2.7 specs for MatchData.allocate in CI

Author: eregon

ci.jsonnet

@@ -281,8 +281,8 @@ local part_definitions = {
   run: {
     test_unit_tck_specs: {
       run+: jt(["test", "unit"]) + jt(["test", "tck"]) +
-            jt(["test", "specs"] + self["$.run.specs"].test_spec_options),
-      # + jt(["test", "specs", ":next"]) disabled as it's currently empty and MSpec doesn't support empty sets of files
+            jt(["test", "specs"] + self["$.run.specs"].test_spec_options) +
+            jt(["test", "specs", ":next"] + self["$.run.specs"].test_spec_options),
     },
 
     test_fast: {

spec/truffle.mspec

@@ -94,6 +94,7 @@ class MSpecScript
   ]
 
   set :next, [
+    "spec/ruby/core/matchdata/allocate_spec.rb",
   ]
 
   set :backtrace_filter, /mspec\//