massive instruction rewrite

So, I ended up moving exec methods from Instruction to Cpu for
encapsulating cycle emulation, and this has caused me lots of pain since
I had to rewrite a shit ton of tests which are not even useful or
comprehensible, i do no know why i put myself through this

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

include/cpu/thumb/instruction.hh

@@ -251,7 +251,7 @@ struct UnconditionalBranch {
 
 struct LongBranchWithLink {
     uint16_t offset;
-    bool high;
+    bool low;
 };
 
 using InstructionData = std::variant<MoveShiftedRegister,