YJIT: Support invokesuper in a block (#7264)

Support invokesuper in a block on YJIT

invokesuper previously side exited when it is in a block. To make sure we're compiling the correct method in super, we now use the local environment pointer (LEP) to get the method, which will work in a block.

Co-authored-by: John Hawthorn <john@hawthorn.email>

bootstraptest/test_yjit.rb

@@ -1940,6 +1940,38 @@ def foo
   ins.foo
 }
 
+# invokesuper with a block
+assert_equal 'true', %q{
+  class A
+    def foo = block_given?
+  end
+
+  class B < A
+    def foo = super()
+  end
+
+  B.new.foo { }
+  B.new.foo { }
+}
+
+# invokesuper in a block
+assert_equal '[0, 2]', %q{
+  class A
+    def foo(x) = x * 2
+  end
+
+  class B < A
+    def foo
+      2.times.map do |x|
+        super(x)
+      end
+    end
+  end
+
+  B.new.foo
+  B.new.foo
+}
+
 # Call to fixnum
 assert_equal '[true, false]', %q{
   def is_odd(obj)

yjit/src/codegen.rs

@@ -6623,22 +6623,15 @@ fn gen_invokesuper(
     // Guard that the receiver has the same class as the one from compile time
     let side_exit = get_side_exit(jit, ocb, ctx);
 
-    let cfp = unsafe { get_ec_cfp(jit.ec.unwrap()) };
-    let ep = unsafe { get_cfp_ep(cfp) };
-    let cref_me = unsafe { *ep.offset(VM_ENV_DATA_INDEX_ME_CREF.try_into().unwrap()) };
-    let me_as_value = VALUE(me as usize);
-    if cref_me != me_as_value {
-        // This will be the case for super within a block
-        return CantCompile;
-    }
-
     asm.comment("guard known me");
-    let ep_opnd = asm.load(Opnd::mem(64, CFP, RUBY_OFFSET_CFP_EP));
+    let lep_opnd = gen_get_lep(jit, asm);
     let ep_me_opnd = Opnd::mem(
         64,
-        ep_opnd,
+        lep_opnd,
         SIZEOF_VALUE_I32 * VM_ENV_DATA_INDEX_ME_CREF,
     );
+
+    let me_as_value = VALUE(me as usize);
     asm.cmp(ep_me_opnd, me_as_value.into());
     asm.jne(counted_exit!(ocb, side_exit, invokesuper_me_changed));
 
@@ -6650,11 +6643,9 @@ fn gen_invokesuper(
         // TODO: this could properly forward the current block handler, but
         // would require changes to gen_send_*
         asm.comment("guard no block given");
-        // EP is in REG0 from above
-        let ep_opnd = asm.load(Opnd::mem(64, CFP, RUBY_OFFSET_CFP_EP));
         let ep_specval_opnd = Opnd::mem(
             64,
-            ep_opnd,
+            lep_opnd,
             SIZEOF_VALUE_I32 * VM_ENV_DATA_INDEX_SPECVAL,
         );
         asm.cmp(ep_specval_opnd, VM_BLOCK_HANDLER_NONE.into());