close #9534 add testcase (#17607)

tests/template/t9534.nim

@@ -0,0 +1,21 @@
+discard """
+  targets: "c cpp"
+"""
+
+# bug #9534
+type
+  Object = object
+    data: int
+
+template test() =
+  proc methodName(o: Object): int =
+    var p: pointer
+    doAssert o.data == 521
+    let f {.used.} = cast[proc (o: int): int {.nimcall.}](p)
+    doAssert o.data == 521
+    result = 1314
+
+  var a = Object(data: 521)
+  doAssert methodName(a) == 1314
+
+test()