tools: force ld.gold

This is to work around a linker bug affecting the NDK.

Reference: android/ndk#602

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/tools/CMakeLists.txt

@@ -1,6 +1,9 @@
 cmake_minimum_required(VERSION 3.4.1)
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_LIBRARY_OUTPUT_DIRECTORY}")
 
+# Work around https://github.com/android-ndk/ndk/issues/602
+set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fuse-ld=gold")
+
 add_executable(libwg-quick.so wireguard-android-integration/wg-quick.c)
 target_compile_options(libwg-quick.so PUBLIC -O3 -std=gnu11 -Wall -pedantic -Wno-missing-field-initializers -DWG_CONFIG_SEARCH_PATHS=\"\\\"/data/data/com.wireguard.android/files\\\"\")