ZJIT: Handle opt_case_dispatch insn (ruby#14433)

ZJIT: Handle opt_case_dispatch insn

Author: st0012

test/ruby/test_zjit.rb

@@ -2240,6 +2240,24 @@ def foo = 1
     }
   end
 
+  def test_opt_case_dispatch
+    assert_compiles '[true, false]', %q{
+      def test(x)
+        case x
+        when :foo
+          true
+        else
+          false
+        end
+      end
+
+      results = []
+      results << test(:foo)
+      results << test(1)
+      results
+    }, insns: [:opt_case_dispatch]
+  end
+
   private
 
   # Assert that every method call in `test_script` can be compiled by ZJIT

zjit/src/hir.rs

@@ -3274,6 +3274,12 @@ pub fn iseq_to_hir(iseq: *const rb_iseq_t) -> Result<Function, ParseError> {
                     });
                     queue.push_back((state.clone(), target, target_idx));
                 }
+                YARVINSN_opt_case_dispatch => {
+                    // TODO: Some keys are visible at compile time, so in the future we can
+                    // compile jump targets for certain cases
+                    // Pop the key from the stack and fallback to the === branches for now
+                    state.stack_pop()?;
+                }
                 YARVINSN_opt_new => {
                     let exit_id = fun.push_insn(block, Insn::Snapshot { state: exit_state });
                     fun.push_insn(block, Insn::CheckInterrupts { state: exit_id });