Convert getinstancevariable to new backend IR (#352)

* Convert getinstancevariable to new backend IR

* Support mem-based mem

* Use more into()

* Add tests for getivar

* Just load obj_opnd to a register

* Apply another into()

* Flip the nil-out condition

* Fix duplicated counts of side_exit

bootstraptest/test_yjit_new_backend.rb

@@ -264,6 +264,22 @@ def foo()
     foo()
 }
 
+# getinstancevariable
+assert_equal '[nil, 1]', %q{
+    class Foo
+      def foo()
+        @foo
+      end
+    end
+
+    @bar = 1
+    def bar
+      @bar
+    end
+
+    [Foo.new.foo, bar]
+}
+
 
 
 

yjit/src/backend/ir.rs

@@ -340,7 +340,14 @@ impl Target
     pub fn unwrap_label_idx(&self) -> usize {
         match self {
             Target::Label(idx) => *idx,
-            _ => unreachable!()
+            _ => unreachable!("trying to unwrap {:?} into label", self)
+        }
+    }
+
+    pub fn unwrap_code_ptr(&self) -> CodePtr {
+        match self {
+            Target::CodePtr(ptr) => *ptr,
+            _ => unreachable!("trying to unwrap {:?} into code ptr", self)
         }
     }
 }