In these environments, the architecture name is armv7; recognize that
and enable the relevant runtimes.
Fix building the sanitizer_common library for this target, by using the
right registers for the architecture - this is similar to what
0c391133c9 did for aarch64.
(Still, address sanitizer doesn't support hooking functions at runtime
on armv7 or aarch64 - but other runtimes such as ubsan do work.)
5ea9dd8c70