linux-user/riscv: Propagate fault address
The CPU loop tagged all the queued signals as QEMU_SI_KILL while it was
filling the `_sigfault` part of `siginfo`: this caused QEMU to copy the
wrong fields over to the userspace program.
Make sure the fault address recorded by the MMU is is stored in the CPU
environment structure.
In case of memory faults store the exception address into `siginfo`.
Signed-off-by: Giuseppe Musacchio <thatlemon@gmail.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>