[unicode] Add HB_UNICODE_MAX

New API:
HB_UNICODE_MAX

docs/harfbuzz-sections.txt

@@ -605,6 +605,7 @@ hb_shape_plan_t
 
 <SECTION>
 <FILE>hb-unicode</FILE>
+HB_UNICODE_MAX
 HB_UNICODE_MAX_DECOMPOSITION_LEN
 hb_unicode_combining_class
 hb_unicode_combining_class_func_t

src/hb-ot-cmap-table.hh

@@ -37,10 +37,6 @@
  */
 #define HB_OT_TAG_cmap HB_TAG('c','m','a','p')
 
-#ifndef HB_MAX_UNICODE_CODEPOINT_VALUE
-#define HB_MAX_UNICODE_CODEPOINT_VALUE 0x10FFFF
-#endif
-
 namespace OT {
 
 
@@ -478,7 +474,7 @@ struct CmapSubtableLongSegmented
     for (unsigned int i = 0; i < this->groups.len; i++) {
       out->add_range (this->groups[i].startCharCode,
 		      MIN ((hb_codepoint_t) this->groups[i].endCharCode,
-			   (hb_codepoint_t) HB_MAX_UNICODE_CODEPOINT_VALUE));
+			   (hb_codepoint_t) HB_UNICODE_MAX));
     }
   }
 
@@ -624,7 +620,7 @@ struct DefaultUVS : SortedArrayOf<UnicodeValueRange, HBUINT32>
     {
       hb_codepoint_t first = arrayZ[i].startUnicodeValue;
       hb_codepoint_t last = MIN ((hb_codepoint_t) (first + arrayZ[i].additionalCount),
-				 (hb_codepoint_t) HB_MAX_UNICODE_CODEPOINT_VALUE);
+				 (hb_codepoint_t) HB_UNICODE_MAX);
       out->add_range (first, last);
     }
   }

src/hb-unicode.h

@@ -40,6 +40,9 @@
 HB_BEGIN_DECLS
 
 
+#define HB_UNICODE_MAX 0x10FFFFu
+
+
 /* hb_unicode_general_category_t */
 
 /* Unicode Character Database property: General_Category (gc) */