In three different places we use the same pattern: an ssl_thread_id_callback()
function (a static member of LLCrashLogger, in that case) that used to be
passed to CRYPTO_set_id_callback() and therefore returned an unsigned long
representing the ID of the current thread.

But GetCurrentThread() is a HANDLE, an alias for a pointer, and you can't
uniquely cram a 64-bit pointer into an unsigned long.

Fortunately OpenSSL has a more modern API for retrieving thread ID. Pass
each ssl_thread_id_callback() function to CRYPTO_THREADID_set_callback()
instead, converting it to accept CRYPTO_THREADID* and call
CRYPTO_THREADID_set_pointer() or CRYPTO_THREADID_set_numeric() as appropriate().