target/xtensa: extract test for cpdisabled exception

- add XtensaOpcodeOps::coprocessor with bitmask of coprocessors used by
  the instruction;
- replace coprocessor id parameter of gen_check_cpenable with the
  bitmask of used coprocessors;
- collect coprocessor IDs used by an instruction in the disassembly
  loop;
- put test for coprocessor disabled exception after the alloca test;

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

target/xtensa/cpu.h

@@ -381,6 +381,7 @@ typedef struct XtensaOpcodeOps {
     const uint32_t *par;
     uint32_t op_flags;
     uint32_t windowed_register_op;
+    uint32_t coprocessor;
 } XtensaOpcodeOps;
 
 typedef struct XtensaOpcodeTranslators {