made tests green again

tests/reject/tenummix.nim

@@ -1,6 +1,6 @@
 discard """
   file: "system.nim"
-  line: 641
+  line: 643
   errormsg: "type mismatch"
 """
 

tests/reject/tinvalidclosure2.nim

@@ -1,6 +1,6 @@
 discard """
   line: 10
-  errormsg: "illegal capture: 'A'"
+  errormsg: "illegal capture 'A'"
 """
 
 proc outer() = 

tests/reject/tnocontains.nim

@@ -7,5 +7,5 @@ discard """
 # shouldn't compile since it doesn't do what you think it does without
 # importing strutils:
 
-let x = "abc" in "abcdef"
+let x = "abcdef".contains("abc")
 echo x

tests/run/tstringinterp.nim

@@ -5,7 +5,7 @@ discard """
 
 import macros, parseutils, strutils
 
-proc concat(strings: openarray[string]): string =
+proc concat(strings: varargs[string]): string =
   result = newString(0)
   for s in items(strings): result.add(s)