Remove unused exports / sections in jni on x86_64.

This resolves a linkage error with x64 affecting Marshmallow and clang.
It also makes the unexported symbols non-visible since they don't need to
be - this reduces the size of the ppsspp_jni.so too.

Unfortunately, it reduces the readability of stack traces.

Author: unknownbrackets

android/jni/Locals.mk

@@ -17,6 +17,13 @@ LOCAL_C_INCLUDES := \
 
 LOCAL_STATIC_LIBRARIES := native libzip glslang
 LOCAL_LDLIBS := -lz -landroid -lGLESv2 -lOpenSLES -lEGL -ldl -llog -latomic
+ifneq ($(NDK_DEBUG),1)
+  # Prettier stack traces are nice on other platforms.
+  # Maybe we can switch to storing the pre-stripped builds at some point.
+  ifeq ($(TARGET_ARCH_ABI),x86_64)
+    LOCAL_LDFLAGS += -Wl,--gc-sections -Wl,--exclude-libs,ALL
+  endif
+endif
 
 # ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
 ifeq ($(findstring armeabi-v7a,$(TARGET_ARCH_ABI)),armeabi-v7a)