Rearrange nre files

tests/stdlib/nre/misc.nim

@@ -0,0 +1,16 @@
+import unittest, nre, strutils, optional_nonstrict
+
+suite "Misc tests":
+  test "unicode":
+    check("".find(re"(*UTF8)").match == "")
+    check("перевірка".replace(re"(*U)\w", "") == "")
+
+  test "empty or non-empty match":
+    check("abc".findall(re"|.").join(":") == ":a::b::c:")
+    check("abc".findall(re".|").join(":") == "a:b:c:")
+
+    check("abc".replace(re"|.", "x") == "xxxxxxx")
+    check("abc".replace(re".|", "x") == "xxxx")
+
+    check("abc".split(re"|.").join(":") == ":::::")
+    check("abc".split(re".|").join(":") == ":::")