Note that since NDK r19, standalone toolchains are auto-generated implicitly by the compiler. You do not need to use the make_standalone_toolchain.py script anymore. You can invoke the Clang compiler directly from the following path:
For your convenience, and for use in automated scripts, the NDK for Linux is hosted on a Google repository. The direct download link for the r23b version follows a predictable pattern: download androidndkr23blinuxx8664zip hot