Fix building Android release versions

With out -03 -flto=full android builds will fail with a message that
it's not possible wiht out O1 - O3

CMakeLists.txt

@@ -189,16 +189,7 @@ endif()
 
 if(ANDROID)
   list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/android-project/CMake")
-
-  set(ASAN OFF)
-  set(UBSAN OFF)
-  set(DEVILUTIONX_SYSTEM_LIBSODIUM OFF)
-  set(DISABLE_ZERO_TIER ON)
-  set(TTF_FONT_DIR \"\")
-
-  file(
-    COPY "${DevilutionX_SOURCE_DIR}/Packaging/resources/CharisSILB.ttf"
-    DESTINATION "${DevilutionX_SOURCE_DIR}/android-project/app/src/main/assets")
+  include(android_defs)
 endif()
 
 if(PIE)

android-project/CMake/android_defs.cmake

@@ -0,0 +1,17 @@
+#General compilation options
+set(ASAN OFF)
+set(UBSAN OFF)
+set(DEVILUTIONX_SYSTEM_LIBSODIUM OFF)
+set(DISABLE_ZERO_TIER ON)
+
+if(BINARY_RELEASE OR CMAKE_BUILD_TYPE STREQUAL "Release")
+  # Workaroudn linker bug in CLang: https://github.com/android/ndk/issues/721
+  set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3 -flto=full")
+endif()
+
+#additional compilation definitions
+set(TTF_FONT_DIR \"\")
+
+file(
+  COPY "${DevilutionX_SOURCE_DIR}/Packaging/resources/CharisSILB.ttf"
+  DESTINATION "${DevilutionX_SOURCE_DIR}/android-project/app/src/main/assets")

android-project/app/build.gradle

@@ -22,7 +22,7 @@ android {
         versionName "1.2.1"
         externalNativeBuild {
             cmake {
-                arguments "-DANDROID_APP_PLATFORM=android-21", "-DANDROID_STL=c++_static"
+                arguments "-DANDROID_STL=c++_static"
                 abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
             }
         }