Fixes #2323. Fixes #2148.

tests/js/taddr.nim

@@ -0,0 +1,36 @@
+type T = object
+  x: int
+  s: string
+
+var obj: T
+var fieldAddr = addr(obj.x)
+var objAddr = addr(obj)
+
+# Integer tests
+var field = fieldAddr[]
+doAssert field == 0
+
+var objDeref = objAddr[]
+doAssert objDeref.x == 0
+
+# Change value
+obj.x = 42
+
+doAssert field == 0
+doAssert objDeref.x == 0
+
+field = fieldAddr[]
+objDeref = objAddr[]
+
+doAssert field == 42
+doAssert objDeref.x == 42
+
+# String tests
+obj.s = "lorem ipsum dolor sit amet"
+var indexAddr = addr(obj.s[2])
+
+doAssert indexAddr[] == '4'
+
+indexAddr[] = 'd'
+
+doAssert indexAddr[] == 'd'