[Berberis][CrashReporting] Extend ThreadInfo to have guest registers

This CL is to get guest registers information.

Bug: b/321799516
Test: m
Testing for TLS Slot:
Manual testing by: 1. crash the jni tests to produce tombstones file 2.
get the signature field of guest state header 3. verified it is the same
value as NATIVE_BRIDGE_GUEST_STATE_SIGNATURE

Manual test the arm64 by: 1. flash build to pixel phone and verify
retrieving TLS_SLOT_THREAD_ID's tid field is the same as current thread
id.

Testing for register values:
Test and print out registers values for riscv64, looks make sense that
has null zero value slots.

Change-Id: Iff44ac5c2b202e44f3fb4e6909fbea141e54ae6b