Character range uncanonicalization.

src/unicode.h

Index: src/unicode.h
diff --git a/src/unicode.h b/src/unicode.h
index fc4003d32395bdeeeb2546a5641bb3550f3cf8a2..e9b92bfdb6397a4c3a9c517ab4e88ef1bfaa5e1f 100644
--- a/src/unicode.h
+++ b/src/unicode.h
@@ -80,12 +80,13 @@ class Mapping {
   friend class Test;
   int CalculateValue(uchar c, uchar n, uchar* result);
   struct CacheEntry {
-    inline CacheEntry() : code_point_(0), offset_(0) { }
+    inline CacheEntry() : code_point_(kNoChar), offset_(0) { }
     inline CacheEntry(uchar code_point, signed offset)
       : code_point_(code_point),
         offset_(offset) { }
     uchar code_point_ : 21;
     signed offset_ : 21;
+    static const int kNoChar = (1 << 21) - 1;
   };
   static const int kSize = size;
   static const int kMask = kSize - 1;
@@ -265,6 +266,13 @@ struct Ecma262UnCanonicalize {
                      uchar* result,
                      bool* allow_caching_ptr);
 };
+struct CanonicalizationRange {
+  static const int kMaxWidth = 1;
+  static int Convert(uchar c,
+                     uchar n,
+                     uchar* result,
+                     bool* allow_caching_ptr);
+};
 
 }  // namespace unibrow