Those are architectures for the processor. Those directories contain native libraries (written in C/C++ instead of Java as usual android code). The old two folders are 32 bit ARM/phone and 32 bit x86/PC. Now they have added 64 bit versions for newer phones/computers. Can you list the contents it would be interesting to see if they added any new libraries.
ls -lahR
.:
total 28K
drwxr-xr-x 7 root root 4.0K Jun 5 11:42 .
drwxr-xr-x 13 root root 4.0K Jun 5 11:42 ..
drwxr-xr-x 2 root root 4.0K Jun 5 11:42 arm64-v8a
drwxr-xr-x 2 root root 4.0K Jun 5 11:42 armeabi
drwxr-xr-x 2 root root 4.0K Jun 5 11:42 armeabi-v7a
drwxr-xr-x 2 root root 4.0K Jun 5 11:42 x86
drwxr-xr-x 2 root root 4.0K Jun 5 11:42 x86_64
./arm64-v8a:
total 26M
drwxr-xr-x 2 root root 4.0K Jun 5 11:42 .
drwxr-xr-x 7 root root 4.0K Jun 5 11:42 ..
-rw-r--r-- 1 root root 1.2M Dec 31 1979 libBaiduMapSDK_base_v4_0_0.so
-rw-r--r-- 1 root root 22K Dec 31 1979 libBaiduMapSDK_cloud_v4_0_0.so
-rw-r--r-- 1 root root 2.0M Dec 31 1979 libBaiduMapSDK_map_v4_0_0.so
-rw-r--r-- 1 root root 38K Dec 31 1979 libBaiduMapSDK_radar_v4_0_0.so
-rw-r--r-- 1 root root 210K Dec 31 1979 libBaiduMapSDK_search_v4_0_0.so
-rw-r--r-- 1 root root 50K Dec 31 1979 libBaiduMapSDK_util_v4_0_0.so
-rw-r--r-- 1 root root 6.5M Dec 31 1979 libc++_shared.so
-rw-r--r-- 1 root root 179K Dec 31 1979 libfb.so
-rw-r--r-- 1 root root 307K Dec 31 1979 libfolly_json.so
-rw-r--r-- 1 root root 31K Dec 31 1979 libglog_init.so
-rw-r--r-- 1 root root 119K Dec 31 1979 libglog.so
-rw-r--r-- 1 root root 391K Dec 31 1979 libimagepipeline.so
-rw-r--r-- 1 root root 291K Dec 31 1979 libjscexecutor.so
-rw-r--r-- 1 root root 13M Dec 31 1979 libjsc.so
-rw-r--r-- 1 root root 47K Dec 31 1979 libjsinspector.so
-rw-r--r-- 1 root root 931K Dec 31 1979 libreactnativejni.so
-rw-r--r-- 1 root root 239K Dec 31 1979 libyoga.so
./armeabi:
total 2.0M
drwxr-xr-x 2 root root 4.0K Jun 5 11:42 .
drwxr-xr-x 7 root root 4.0K Jun 5 11:42 ..
-rw-r--r-- 1 root root 677K Dec 31 1979 libBaiduMapSDK_base_v4_0_0.so
-rw-r--r-- 1 root root 22K Dec 31 1979 libBaiduMapSDK_cloud_v4_0_0.so
-rw-r--r-- 1 root root 1.1M Dec 31 1979 libBaiduMapSDK_map_v4_0_0.so
-rw-r--r-- 1 root root 30K Dec 31 1979 libBaiduMapSDK_radar_v4_0_0.so
-rw-r--r-- 1 root root 138K Dec 31 1979 libBaiduMapSDK_search_v4_0_0.so
-rw-r--r-- 1 root root 38K Dec 31 1979 libBaiduMapSDK_util_v4_0_0.so
./armeabi-v7a:
total 19M
drwxr-xr-x 2 root root 4.0K Jun 5 11:42 .
drwxr-xr-x 7 root root 4.0K Jun 5 11:42 ..
-rw-r--r-- 1 root root 661K Dec 31 1979 libBaiduMapSDK_base_v4_0_0.so
-rw-r--r-- 1 root root 22K Dec 31 1979 libBaiduMapSDK_cloud_v4_0_0.so
-rw-r--r-- 1 root root 1.1M Dec 31 1979 libBaiduMapSDK_map_v4_0_0.so
-rw-r--r-- 1 root root 30K Dec 31 1979 libBaiduMapSDK_radar_v4_0_0.so
-rw-r--r-- 1 root root 134K Dec 31 1979 libBaiduMapSDK_search_v4_0_0.so
-rw-r--r-- 1 root root 34K Dec 31 1979 libBaiduMapSDK_util_v4_0_0.so
-rw-r--r-- 1 root root 4.7M Dec 31 1979 libc++_shared.so
-rw-r--r-- 1 root root 134K Dec 31 1979 libfb.so
-rw-r--r-- 1 root root 298K Dec 31 1979 libfolly_json.so
-rw-r--r-- 1 root root 18K Dec 31 1979 libglog_init.so
-rw-r--r-- 1 root root 94K Dec 31 1979 libglog.so
-rw-r--r-- 1 root root 250K Dec 31 1979 libimagepipeline.so
-rw-r--r-- 1 root root 222K Dec 31 1979 libjscexecutor.so
-rw-r--r-- 1 root root 9.7M Dec 31 1979 libjsc.so
-rw-r--r-- 1 root root 34K Dec 31 1979 libjsinspector.so
-rw-r--r-- 1 root root 742K Dec 31 1979 libreactnativejni.so
-rw-r--r-- 1 root root 174K Dec 31 1979 libyoga.so
./x86:
total 25M
drwxr-xr-x 2 root root 4.0K Jun 5 11:42 .
drwxr-xr-x 7 root root 4.0K Jun 5 11:42 ..
-rw-r--r-- 1 root root 1.3M Dec 31 1979 libBaiduMapSDK_base_v4_0_0.so
-rw-r--r-- 1 root root 18K Dec 31 1979 libBaiduMapSDK_cloud_v4_0_0.so
-rw-r--r-- 1 root root 2.4M Dec 31 1979 libBaiduMapSDK_map_v4_0_0.so
-rw-r--r-- 1 root root 38K Dec 31 1979 libBaiduMapSDK_radar_v4_0_0.so
-rw-r--r-- 1 root root 234K Dec 31 1979 libBaiduMapSDK_search_v4_0_0.so
-rw-r--r-- 1 root root 54K Dec 31 1979 libBaiduMapSDK_util_v4_0_0.so
-rw-r--r-- 1 root root 5.6M Dec 31 1979 libc++_shared.so
-rw-r--r-- 1 root root 170K Dec 31 1979 libfb.so
-rw-r--r-- 1 root root 318K Dec 31 1979 libfolly_json.so
-rw-r--r-- 1 root root 26K Dec 31 1979 libglog_init.so
-rw-r--r-- 1 root root 114K Dec 31 1979 libglog.so
-rw-r--r-- 1 root root 462K Dec 31 1979 libimagepipeline.so
-rw-r--r-- 1 root root 282K Dec 31 1979 libjscexecutor.so
-rw-r--r-- 1 root root 13M Dec 31 1979 libjsc.so
-rw-r--r-- 1 root root 42K Dec 31 1979 libjsinspector.so
-rw-r--r-- 1 root root 906K Dec 31 1979 libreactnativejni.so
-rw-r--r-- 1 root root 258K Dec 31 1979 libyoga.so
./x86_64:
total 27M
drwxr-xr-x 2 root root 4.0K Jun 5 11:42 .
drwxr-xr-x 7 root root 4.0K Jun 5 11:42 ..
-rw-r--r-- 1 root root 1.3M Dec 31 1979 libBaiduMapSDK_base_v4_0_0.so
-rw-r--r-- 1 root root 22K Dec 31 1979 libBaiduMapSDK_cloud_v4_0_0.so
-rw-r--r-- 1 root root 2.3M Dec 31 1979 libBaiduMapSDK_map_v4_0_0.so
-rw-r--r-- 1 root root 38K Dec 31 1979 libBaiduMapSDK_radar_v4_0_0.so
-rw-r--r-- 1 root root 210K Dec 31 1979 libBaiduMapSDK_search_v4_0_0.so
-rw-r--r-- 1 root root 54K Dec 31 1979 libBaiduMapSDK_util_v4_0_0.so
-rw-r--r-- 1 root root 6.3M Dec 31 1979 libc++_shared.so
-rw-r--r-- 1 root root 179K Dec 31 1979 libfb.so
-rw-r--r-- 1 root root 307K Dec 31 1979 libfolly_json.so
-rw-r--r-- 1 root root 31K Dec 31 1979 libglog_init.so
-rw-r--r-- 1 root root 139K Dec 31 1979 libglog.so
-rw-r--r-- 1 root root 479K Dec 31 1979 libimagepipeline.so
-rw-r--r-- 1 root root 295K Dec 31 1979 libjscexecutor.so
-rw-r--r-- 1 root root 14M Dec 31 1979 libjsc.so
-rw-r--r-- 1 root root 43K Dec 31 1979 libjsinspector.so
-rw-r--r-- 1 root root 943K Dec 31 1979 libreactnativejni.so
-rw-r--r-- 1 root root 247K Dec 31 1979 libyoga.so