Switch from ICU deprecated unorm_normalize to unorm2_normalize. (#569)

The new unorm2_normalize has been public API since ICU 4.4, while
the old unorm_normalize has been deprecated since ICU 56.

Now, beginning with ICU 60, unorm_normalize will also be annotated
U_DEPRECATED and trigger the compiler -Wdeprecated-declarations warning.

src/hb-icu.cc

@@ -34,7 +34,7 @@
 #include "hb-unicode-private.hh"
 
 #include <unicode/uchar.h>
-#include <unicode/unorm.h>
+#include <unicode/unorm2.h>
 #include <unicode/ustring.h>
 #include <unicode/utf16.h>
 #include <unicode/uversion.h>
@@ -200,7 +200,7 @@ hb_icu_unicode_compose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
   if (err) return false;
 
   icu_err = U_ZERO_ERROR;
-  len = unorm_normalize (utf16, len, UNORM_NFC, 0, normalized, ARRAY_LENGTH (normalized), &icu_err);
+  len = unorm2_normalize (unorm2_getNFCInstance (&icu_err), utf16, len, normalized, ARRAY_LENGTH (normalized), &icu_err);
   if (U_FAILURE (icu_err))
     return false;
   if (u_countChar32 (normalized, len) == 1) {
@@ -261,7 +261,7 @@ hb_icu_unicode_decompose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
   if (err) return false;
 
   icu_err = U_ZERO_ERROR;
-  len = unorm_normalize (utf16, len, UNORM_NFD, 0, normalized, ARRAY_LENGTH (normalized), &icu_err);
+  len = unorm2_normalize (unorm2_getNFDInstance (&icu_err), utf16, len, normalized, ARRAY_LENGTH (normalized), &icu_err);
   if (U_FAILURE (icu_err))
     return false;
 
@@ -281,7 +281,7 @@ hb_icu_unicode_decompose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
      * the second part :-(. */
     UChar recomposed[20];
     icu_err = U_ZERO_ERROR;
-    unorm_normalize (normalized, len, UNORM_NFC, 0, recomposed, ARRAY_LENGTH (recomposed), &icu_err);
+    unorm2_normalize (unorm2_getNFCInstance (&icu_err), normalized, len, recomposed, ARRAY_LENGTH (recomposed), &icu_err);
     if (U_FAILURE (icu_err))
       return false;
     hb_codepoint_t c;
@@ -297,7 +297,7 @@ hb_icu_unicode_decompose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
     U16_PREV_UNSAFE (normalized, len, *b); /* Changes len in-place. */
     UChar recomposed[18 * 2];
     icu_err = U_ZERO_ERROR;
-    len = unorm_normalize (normalized, len, UNORM_NFC, 0, recomposed, ARRAY_LENGTH (recomposed), &icu_err);
+    len = unorm2_normalize (unorm2_getNFCInstance (&icu_err), normalized, len, recomposed, ARRAY_LENGTH (recomposed), &icu_err);
     if (U_FAILURE (icu_err))
       return false;
     /* We expect that recomposed has exactly one character now. */
@@ -331,7 +331,7 @@ hb_icu_unicode_decompose_compatibility (hb_unicode_funcs_t *ufuncs HB_UNUSED,
 
   /* Normalise the codepoint using NFKD mode. */
   icu_err = U_ZERO_ERROR;
-  len = unorm_normalize (utf16, len, UNORM_NFKD, 0, normalized, ARRAY_LENGTH (normalized), &icu_err);
+  len = unorm2_normalize (unorm2_getNFKDInstance (&icu_err), utf16, len, normalized, ARRAY_LENGTH (normalized), &icu_err);
   if (icu_err)
     return 0;