Android: Attach CPU thread to JVM early

Source/Core/Core/CMakeLists.txt

@@ -583,6 +583,11 @@ if (APPLE)
     ${IOB_LIBRARY}
     ${IOK_LIBRARY}
   )
+elseif (ANDROID)
+  target_link_libraries(core
+  PRIVATE
+    androidcommon
+  )
 endif()
 
 if(LIBUSB_FOUND)

Source/Core/Core/Core.cpp

@@ -85,6 +85,10 @@
 #include "VideoCommon/VideoBackendBase.h"
 #include "VideoCommon/VideoConfig.h"
 
+#ifdef ANDROID
+#include "jni/AndroidCommon/IDCache.h"
+#endif
+
 namespace Core
 {
 static bool s_wants_determinism;
@@ -335,6 +339,12 @@ static void CpuThread(const std::optional<std::string>& savestate_path, bool del
   // This needs to be delayed until after the video backend is ready.
   DolphinAnalytics::Instance().ReportGameStart();
 
+#ifdef ANDROID
+  // For some reason, calling the JNI function AttachCurrentThread from the CPU thread after a
+  // certain point causes a crash if fastmem is enabled. Let's call it early to avoid that problem.
+  static_cast<void>(IDCache::GetEnvForThread());
+#endif
+
   if (_CoreParameter.bFastmem)
     EMM::InstallExceptionHandler();  // Let's run under memory watch