Port gen_concatstring to new backend IR (https://github.com/Shopify/ruby/pull/350)

* Port gen_concatstring to new backend IR

* Update yjit/src/codegen.rs

Co-authored-by: Maxime Chevalier-Boisvert <maximechevalierb@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/bootstraptest/test_yjit.rb b/bootstraptest/test_yjit.rb
index b8374746f7..2409306106 100644
--- a/bootstraptest/test_yjit.rb
+++ b/bootstraptest/test_yjit.rb
@@ -3103,3 +3103,11 @@ assert_equal '/true/', %q{
     end
     foo().inspect
 }
+
+# concatstrings
+assert_equal '9001', %q{
+    def foo()
+      "#{9001}"
+    end
+    foo()
+}