build: link to ICU by full path on Android

Use the variable that holds the path to the ICU libraries to link
against ICU rather than hardcoding the names.  This restores control to
the ICU linking to the way that traditional CMake `find_package` based
linking works.

Author: compnerd

cmake/modules/AddSwift.cmake

@@ -462,9 +462,10 @@ function(_add_variant_link_flags)
     list(APPEND link_libraries "bsd" "atomic")
     list(APPEND result "-Wl,-Bsymbolic")
   elseif("${LFLAGS_SDK}" STREQUAL "ANDROID")
-    list(APPEND link_libraries "dl" "log" "atomic" "icudataswift" "icui18nswift" "icuucswift")
+    list(APPEND link_libraries "dl" "log" "atomic")
     # We need to add the math library, which is linked implicitly by libc++
     list(APPEND result "-lm")
+
     if("${LFLAGS_ARCH}" MATCHES armv7)
       set(android_libcxx_path "${SWIFT_ANDROID_NDK_PATH}/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a")
     elseif("${LFLAGS_ARCH}" MATCHES aarch64)
@@ -476,8 +477,17 @@ function(_add_variant_link_flags)
     else()
       message(SEND_ERROR "unknown architecture (${LFLAGS_ARCH}) for android")
     endif()
-    list(APPEND link_libraries "${android_libcxx_path}/libc++abi.a")
-    list(APPEND link_libraries "${android_libcxx_path}/libc++_shared.so")
+
+    # link against the custom C++ library
+    list(APPEND link_libraries
+      ${android_libcxx_path}/libc++abi.a
+      ${android_libcxx_path}/libc++_shared.so)
+
+    # link against the ICU libraries
+    list(APPEND link_libraries
+      ${SWIFT_ANDROID_${LFLAGS_ARCH}_ICU_I18N}
+      ${SWIFT_ANDROID_${LFLAGS_ARCH}_ICU_UC})
+
     swift_android_lib_for_arch(${LFLAGS_ARCH} ${LFLAGS_ARCH}_LIB)
     foreach(path IN LISTS ${LFLAGS_ARCH}_LIB)
       list(APPEND library_search_directories ${path})