Port gen_send_cfunc to the new backend (#357)

* Port gen_send_cfunc to the new backend

* Remove an obsoleted test

* Add more cfunc tests

* Use csel_e instead and more into()

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

* Add a missing lea for build_kwargs

* Split cfunc test cases

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

bootstraptest/test_yjit_new_backend.rb

@@ -144,6 +144,38 @@ def foo()
     foo()
 }
 
+# opt_send_without_block (VM_METHOD_TYPE_CFUNC)
+assert_equal 'nil', %q{
+    def foo
+      nil.inspect # argc: 0
+    end
+    foo
+}
+assert_equal '4', %q{
+    def foo
+      2.pow(2) # argc: 1
+    end
+    foo
+}
+assert_equal 'aba', %q{
+    def foo
+      "abc".tr("c", "a") # argc: 2
+    end
+    foo
+}
+assert_equal 'true', %q{
+    def foo
+      respond_to?(:inspect) # argc: -1
+    end
+    foo
+}
+assert_equal '["a", "b"]', %q{
+    def foo
+      "a\nb".lines(chomp: true) # kwargs
+    end
+    foo
+}
+
 # opt_send_without_block (VM_METHOD_TYPE_ATTRSET)
 assert_equal 'foo', %q{
     class Foo