Add the third stack pointer, the Interrupt Stack Pointer (ISP)
(680x0 only). This stack will be needed in softmmu mode.
Update movec to set/get the value of the three stacks.
Backports commit 6e22b28e22aa6ed1b8db6f24da2633868019d4c9 from qemu
The instruction traps if the CPU is not in
Supervisor state but the helper is empty because
there is no easy way to reset all the peripherals
without resetting the CPU itself.
Backports commit 0bdb2b3bf5660f892ddbfa09baea56cdca57ad1d from qemu
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.
Backports commit fcf5ef2ab52c621a4617ebbef36bf43b4003f4c0 from qemu
