[lldb/crashlog] Make registers always available & fix x29/x30 parsing (#145104)
This patch addresses 2 issues:
1. It makes registers available on non-crashed threads all the time
2. It fixes arm64 registers parsing for registers that don't use the `x`
prefix (`fp` -> `x29` / `lr` -> `x30`)
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Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>