ZJIT: Optimize GetIvar for non-T_OBJECT

* All Invariant::SingleRactorMode PatchPoint are replaced by
  assume_single_ractor_mode() to fix https://github.com/Shopify/ruby/issues/875
  for SingleRactorMode patchpoints.

1 files changed, 29 insertions, 1 deletions

diff --git a/test/ruby/test_zjit.rb b/test/ruby/test_zjit.rb
index d821d8ad5c..6609bb2461 100644
--- a/test/ruby/test_zjit.rb
+++ b/test/ruby/test_zjit.rb
@@ -3017,7 +3017,35 @@ class TestZJIT < Test::Unit::TestCase
       test
 
       Ractor.new { test }.value
-    }
+    }, call_threshold: 2
+  end
+
+  def test_ivar_get_with_already_multi_ractor_mode
+    assert_compiles '42', %q{
+      class Foo
+        def self.set_bar
+          @bar = [] # needs to be a ractor unshareable object
+        end
+
+        def self.bar
+          @bar
+        rescue Ractor::IsolationError
+          42
+        end
+      end
+
+      Foo.set_bar
+      r = Ractor.new {
+        Ractor.receive
+        Foo.bar
+      }
+
+      Foo.bar
+      Foo.bar
+
+      r << :go
+      r.value
+    }, call_threshold: 2
   end
 
   def test_ivar_set_with_multi_ractor_mode