[cmake] Find ICU in CoreFoundation.

ICU is also included in CoreFoundation, but the include paths were
not used, which meant that the headers were probably the system
headers, if they were there. This might have work in Ubuntu, but
might not work in other systems with older ICUs.

The patch passes the ICU_ROOT from the top level CMakeList.txt into
the CoreFoundation one and performs a find_package to find the right
include path.

Author: drodriguez

CMakeLists.txt

@@ -39,6 +39,7 @@ ExternalProject_Add(CoreFoundation
                       -DCF_ENABLE_LIBDISPATCH=${FOUNDATION_ENABLE_LIBDISPATCH}
                       -DCF_PATH_TO_LIBDISPATCH_SOURCE=${FOUNDATION_PATH_TO_LIBDISPATCH_SOURCE}
                       -DCF_PATH_TO_LIBDISPATCH_BUILD=${FOUNDATION_PATH_TO_LIBDISPATCH_BUILD}
+                      -DICU_ROOT=${ICU_ROOT}
                     INSTALL_COMMAND
                       ${CMAKE_COMMAND} -E env --unset=DESTDIR ${CMAKE_COMMAND} --build . --target install)
 ExternalProject_Get_Property(CoreFoundation install_dir)

CoreFoundation/CMakeLists.txt

@@ -1,7 +1,8 @@
 
 cmake_minimum_required(VERSION 3.4.3)
 list(APPEND CMAKE_MODULE_PATH
-     "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules")
+     "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules"
+     "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/modules")
 
 project(CoreFoundation
         VERSION
@@ -352,6 +353,10 @@ if(CMAKE_SYSTEM_NAME STREQUAL Linux OR CMAKE_SYSTEM_NAME STREQUAL Android)
   target_include_directories(CoreFoundation
                              PRIVATE
                                ${CURL_INCLUDE_DIRS})
+  find_package(ICU COMPONENTS uc i18n REQUIRED)
+  target_include_directories(CoreFoundation
+                             PRIVATE
+                               ${ICU_INCLUDE_DIRS})
 else()
   target_include_directories(CoreFoundation
                              PRIVATE