[hwasan] Remove lazy thread-initialisation
This was an experiment made possible by a non-standard feature of the
Android dynamic loader.
It required introducing a flag to tell the compiler which ABI was being
This flag is no longer needed, since the generated code now works for
We leave that flag untouched for backwards compatibility. This also
means that if we need to distinguish between targeted ABI's again
we can do that without disturbing any existing workflows.
We leave a comment in the source code and mention in the help text to
explain this for any confused person reading the code in the future.
Patch by Matthew Malcomson
Differential Revision: https://reviews.llvm.org/D69574