Revert of [regexp] implement character classes for unicode regexps.

src/ostreams.h

Index: src/ostreams.h
diff --git a/src/ostreams.h b/src/ostreams.h
index 1c2f38a1539e6ed42736a5f8b6ae82200f27c367..56f4aa7e45b766392699c6d36e49793071f0989d 100644
--- a/src/ostreams.h
+++ b/src/ostreams.h
@@ -50,12 +50,6 @@
 };
 
 
-struct AsUC32 {
-  explicit AsUC32(int32_t v) : value(v) {}
-  int32_t value;
-};
-
-
 struct AsReversiblyEscapedUC16 {
   explicit AsReversiblyEscapedUC16(uint16_t v) : value(v) {}
   uint16_t value;
@@ -79,10 +73,6 @@
 // of printable ASCII range.
 std::ostream& operator<<(std::ostream& os, const AsUC16& c);
 
-// Writes the given character to the output escaping everything outside
-// of printable ASCII range.
-std::ostream& operator<<(std::ostream& os, const AsUC32& c);
-
 }  // namespace internal
 }  // namespace v8