cpu: Introduce CPUState::gdb_num_regs and CPUClass::gdb_num_core_regs

CPUState::gdb_num_regs replaces num_g_regs.
CPUClass::gdb_num_core_regs replaces NUM_CORE_REGS.

Allows building gdb_register_coprocessor() for xtensa, too.

As a side effect this should fix coprocessor register numbering for SMP.

Acked-by: Michael Walle <michael@walle.cc> (for lm32)
Acked-by: Max Filippov <jcmvbkbc@gmail.com> (for xtensa)
Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index cd350cb..df9832e 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2549,6 +2549,7 @@
     cc->write_elf32_qemunote = x86_cpu_write_elf32_qemunote;
     cc->vmsd = &vmstate_x86_cpu;
 #endif
+    cc->gdb_num_core_regs = CPU_NB_REGS * 2 + 25;
 }
 
 static const TypeInfo x86_cpu_type_info = {