YJIT: Make case-when optimization respect === redefinition (#6846)

* YJIT: Make case-when optimization respect === redefinition

Even when a fixnum key is in the dispatch hash, if there is a case such
that its basic operations for === is redefined, we need to fall back to
checking each case like the interpreter. Semantically we're always
checking each case by calling === in order, it's just that this is not
observable when basic operations are intact.

When all the keys are fixnums, though, we can do the optimization we're
doing right now. Check for this condition.

* Update yjit/src/cruby_bindings.inc.rs

Co-authored-by: Takashi Kokubun <takashikkbn@gmail.com>

Co-authored-by: Takashi Kokubun <takashikkbn@gmail.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/bootstraptest/test_yjit.rb b/bootstraptest/test_yjit.rb
index 25085f0e8d..349417595f 100644
--- a/bootstraptest/test_yjit.rb
+++ b/bootstraptest/test_yjit.rb
@@ -3436,3 +3436,23 @@ assert_equal '1', %q{
 
   foo(1)
 }
+
+# case-when with redefined ===
+assert_equal 'ok', %q{
+  class Symbol
+    def ===(a)
+      true
+    end
+  end
+
+  def cw(arg)
+    case arg
+    when :b
+      :ok
+    when 4
+      :ng
+    end
+  end
+
+  cw(4)
+}