[pango: 1/2] Fix build failure on Mac OS X 10.5 and earlier

[Khaled Hosny <khaledh src gnome org>]

commit dce7ba63ed8b0567f674ade72da827d4a4c1b603
Author: Ryan Schmidt <git ryandesign com>
Date:   Sat Aug 4 12:20:02 2018 -0500

    Fix build failure on Mac OS X 10.5 and earlier
    
    Provides definitions of CFStringIsSurrogateHighCharacter,
    CFStringIsSurrogateLowCharacter and CFStringGetLongCharacterForSurrogatePair.
    
    Closes #263

 pango/pangocoretext-shape.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
---
diff --git a/pango/pangocoretext-shape.c b/pango/pangocoretext-shape.c
index 1f46d8a0..061279a9 100644
--- a/pango/pangocoretext-shape.c
+++ b/pango/pangocoretext-shape.c
@@ -29,6 +29,20 @@
 #include "pangocoretext-private.h"
 #include "pango-impl-utils.h"
 
+#if defined(MAC_OS_X_VERSION_MAX_ALLOWED) && MAC_OS_X_VERSION_MAX_ALLOWED < 1060
+CF_INLINE Boolean CFStringIsSurrogateHighCharacter(UniChar character) {
+    return ((character >= 0xD800UL) && (character <= 0xDBFFUL) ? true : false);
+}
+
+CF_INLINE Boolean CFStringIsSurrogateLowCharacter(UniChar character) {
+    return ((character >= 0xDC00UL) && (character <= 0xDFFFUL) ? true : false);
+}
+
+CF_INLINE UTF32Char CFStringGetLongCharacterForSurrogatePair(UniChar surrogateHigh, UniChar surrogateLow) {
+    return ((surrogateHigh - 0xD800UL) << 10) + (surrogateLow - 0xDC00UL) + 0x0010000UL;
+}
+#endif
+
 static void
 set_glyph (PangoFont        *font,
           PangoGlyphString *glyphs,