Add back U_WCHAR_IS_UTF32 macro to pmac.h...

third_party/icu/patches/pmac.h.patch

Index: third_party/icu/patches/pmac.h.patch
===================================================================
--- third_party/icu/patches/pmac.h.patch	(revision 75292)
+++ third_party/icu/patches/pmac.h.patch	(working copy)
@@ -1,7 +1,5 @@
-Index: common/unicode/pmac.h
-===================================================================
---- common/unicode/pmac.h	(revision 69841)
-+++ common/unicode/pmac.h	(working copy)
+--- common/unicode/pmac.h
++++ common/unicode/pmac.h
 @@ -49,14 +49,20 @@
  #define U_DARWIN
  #endif
@@ -36,3 +34,22 @@
  #endif
  #if 1
  #define U_TZNAME        tzname
+@@ -399,4 +407,18 @@
+ 
+ # endif
+ #endif
++
++/*===========================================================================*/
++/* Local defines                                                             */
++/*===========================================================================*/
++
++/* On the Mac, we define U_WCHAR_IS_UTF32 to treat wchar_t as though it
++   contains UTF-32 at all times.  Strictly speaking, that's not entirely
++   correct given Mac's libc (__STDC_ISO_10646__ is not defined) , but provided
++   that we ignore libc's locale support (by not calling setlocale) and its
++   multibyte string support, this should be fine.  Our codebase makes enough
++   other assumptions about a UTF-8 locale and UTF-32 wchar_t strings for this
++   to make sense. */
++#define U_WCHAR_IS_UTF32
++
+ #endif