cc->do_interrupt is in theory a TCG callback used in accel/tcg only,
to prepare the emulated architecture to take an interrupt as defined
in the hardware specifications,
but in reality the _do_interrupt style of functions in targets are
also occasionally reused by KVM to prepare the architecture state in a
similar way where userspace code has identified that it needs to
deliver an exception to the guest.
In the case of ARM, that includes:
1) the vcpu thread got a SIGBUS indicating a memory error,
and we need to deliver a Synchronous External Abort to the guest to
let it know about the error.
2) the kernel told us about a debug exception (breakpoint, watchpoint)
but it is not for one of QEMU's own gdbstub breakpoints/watchpoints
so it must be a breakpoint the guest itself has set up, therefore
we need to deliver it to the guest.
So in order to reuse code, the same arm_do_interrupt function is used.
This is all fine, but we need to avoid calling it using the callback
registered in CPUClass, since that one is now TCG-only.
Fortunately this is easily solved by replacing calls to
CPUClass::do_interrupt() with explicit calls to arm_do_interrupt().
Backports 853bfef4e6d60244fd131ec55bbf1e7caa52599b. We don't support
KVM, so we just bring the comment addition over.