sashs
BUGFIX: gadgets missed because of a bad declaration of the pop pc gadget.
The pattern of a pop pc gadget in arch.py does not cover all the cases, making ropper to miss a lot of gadgets in ARM and ARMBE.
Fix this pattern to identify all possible instructions that ends up in a usable gadget is not an easy task. After a few attempts to fix this pattern myself, I finally decided to use the same pattern that is used in ROPGadget.
I'm not sure that it's perfect, but it's for sure a better version than the current pattern in ropper.
ropper is now able to find gadgets like pop {r4, r5, r6, r7, r8, pc}; in ARM and ARMBE.
Second commit added to handle the detection of the pop {pc} gadget, which is surprisingly not handled by ropper and ROPGadget.
Once again previous commit was bad. It was properly detecting pop {pc} gadgets, but introduced detection of other instructions that are not gadgets like :
$ kstool arm "ldr ip, [r1], #4"
ldr ip, [r1], #4 = [ 04 c0 91 e4 ]
So I added a specific pattern for the detection of a pop {pc} gadget, and kept the original pattern from ROPGadget for everything else.
