Merge branch 'PHP-7.3' into PHP-7.4

* PHP-7.3:
  Fixed bug #80310: Support for icu4c 68.1.

Author: nikic

build/php.m4

@@ -1907,6 +1907,8 @@ AC_DEFUN([PHP_SETUP_ICU],[
   if test "$PKG_CONFIG icu-io --atleast-version=60"; then
     ICU_CFLAGS="$ICU_CFLAGS -DU_HIDE_OBSOLETE_UTF_OLD_H=1"
   fi
+
+  ICU_CFLAGS="$ICU_CFLAGS -DU_DEFINE_FALSE_AND_TRUE=1"
 ])
 
 dnl