fixes #2297, fixes #2946

tests/vm/tswap.nim

@@ -0,0 +1,24 @@
+discard """
+msg: '''
+x.data = @[10]
+y = @[11]
+x.data = @[11]
+y = @[10]'''
+"""
+
+# bug #2946
+
+proc testSwap(): int {.compiletime.} =
+  type T = object
+    data: seq[int]
+  var x: T
+  x.data = @[10]
+  var y = @[11]
+  echo "x.data = ", x.data
+  echo "y = ", y
+  swap(y, x.data)
+  echo "x.data = ", x.data
+  echo "y = ", y
+  result = 99
+
+const something = testSwap()