Build libc++ ourselves

.gitmodules

@@ -28,6 +28,9 @@
 [submodule "xhook"]
 	path = native/jni/external/xhook
 	url = https://github.com/iqiyi/xHook.git
+[submodule "libcxx"]
+	path = native/jni/external/libcxx
+	url = https://github.com/topjohnwu/libcxx.git
 [submodule "termux-elf-cleaner"]
 	path = tools/termux-elf-cleaner
 	url = https://github.com/termux/termux-elf-cleaner.git

native/jni/Application.mk

@@ -3,7 +3,7 @@ APP_CFLAGS := -Wall -Oz -fomit-frame-pointer -flto \
 -D__MVSTR=${MAGISK_VERSION} -D__MCODE=${MAGISK_VER_CODE}
 APP_LDFLAGS := -flto
 APP_CPPFLAGS := -std=c++17
-APP_STL := c++_static
+APP_STL := none
 APP_PLATFORM := android-16
 
 ifdef MAGISK_DEBUG

native/jni/external/Android.mk

@@ -374,3 +374,4 @@ include $(BUILD_STATIC_LIBRARY)
 CWD := $(LOCAL_PATH)
 include $(CWD)/systemproperties/Android.mk
 include $(CWD)/mincrypt/Android.mk
+include $(CWD)/libcxx/Android.mk

native/jni/external/systemproperties/Android.mk

@@ -4,6 +4,7 @@ include $(CLEAR_VARS)
 LOCAL_MODULE:= libsystemproperties
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
 LOCAL_EXPORT_C_INCLUDES := $(LOCAL_C_INCLUDES)
+LOCAL_STATIC_LIBRARIES := libcxx
 LOCAL_SRC_FILES := \
 	context_node.cpp \
 	contexts_serialized.cpp \

native/jni/utils/Android.mk

@@ -4,6 +4,8 @@ include $(CLEAR_VARS)
 LOCAL_MODULE:= libutils
 LOCAL_C_INCLUDES := jni/include $(LOCAL_PATH)/include
 LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
+LOCAL_EXPORT_STATIC_LIBRARIES := libcxx
+LOCAL_STATIC_LIBRARIES := libcxx
 LOCAL_SRC_FILES := \
     missing.cpp \
     new.cpp \