cpu: Turn cpu_get_phys_page_debug() into a CPUClass hook

Change breakpoint_invalidate() argument to CPUState alongside.

Since all targets now assign a softmmu-only field, we can drop helpers
cpu_class_set_{do_unassigned_access,vmsd}() and device_class_set_vmsd().

Prepares for changing cpu_memory_rw_debug() argument to CPUState.

Acked-by: Max Filippov <jcmvbkbc@gmail.com> (for xtensa)
Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/target-i386/helper.c b/target-i386/helper.c
index d6f43d7..2745292 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -884,8 +884,10 @@
     return 1;
 }
 
-hwaddr cpu_get_phys_page_debug(CPUX86State *env, target_ulong addr)
+hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
 {
+    X86CPU *cpu = X86_CPU(cs);
+    CPUX86State *env = &cpu->env;
     target_ulong pde_addr, pte_addr;
     uint64_t pte;
     hwaddr paddr;