merge stdlib tests (#9439)

tests/stdlib/tio.nim

@@ -1,49 +0,0 @@
-discard """
-  output: '''9
-b = true
-123456789
-Second readLine raised an exception
-123456789
-1
-2aaaaaaaa
-3bbbbbbb
-'''
-"""
-# bug #5349
-import os
-
-# test the file-IO
-
-const fn = "file9char.txt"
-
-writeFile(fn, "123456789")
-
-var f = open(fn)
-echo getFileSize(f)
-
-var line = newString(10)
-try:
-  let b = readLine(f, line)
-  echo "b = ", b
-except:
-  echo "First readLine raised an exception"
-
-echo line
-
-try:
-  line = readLine(f)
-  let b = readLine(f, line)
-  echo "b = ", b
-except:
-  echo "Second readLine raised an exception"
-
-echo line
-f.close()
-
-removeFile(fn)
-
-# bug #8961
-writeFile("test.txt", "1\C\L2aaaaaaaa\C\L3bbbbbbb")
-
-for line in lines("test.txt"):
-  echo line