x86/build: limit #include-ing by asm-offsets.c

This file has a long dependencies list and asm-offsets.h, generated from
it, has a long list of dependents. IOW if any of the former changes, all
of the latter will be rebuilt, even if there's no actual change to the
generated file. Therefore avoid including headers we don't actually need
(generally or configuration dependent).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>

xen/arch/x86/x86_64/asm-offsets.c

@@ -5,11 +5,13 @@
  */
 #define COMPILE_OFFSETS
 
+#ifdef CONFIG_PERF_COUNTERS
 #include <xen/perfc.h>
+#endif
 #include <xen/sched.h>
-#include <xen/bitops.h>
+#ifdef CONFIG_PV
 #include <compat/xen.h>
-#include <asm/fixmap.h>
+#endif
 #include <asm/hardirq.h>
 #include <xen/multiboot.h>
 #include <xen/multiboot2.h>
@@ -101,7 +103,6 @@ void __dummy__(void)
 #ifdef CONFIG_PV
     OFFSET(DOMAIN_is_32bit_pv, struct domain, arch.pv.is_32bit);
     BLANK();
-#endif
 
     OFFSET(VCPUINFO_upcall_pending, struct vcpu_info, evtchn_upcall_pending);
     OFFSET(VCPUINFO_upcall_mask, struct vcpu_info, evtchn_upcall_mask);
@@ -110,6 +111,7 @@ void __dummy__(void)
     OFFSET(COMPAT_VCPUINFO_upcall_pending, struct compat_vcpu_info, evtchn_upcall_pending);
     OFFSET(COMPAT_VCPUINFO_upcall_mask, struct compat_vcpu_info, evtchn_upcall_mask);
     BLANK();
+#endif
 
     OFFSET(CPUINFO_guest_cpu_user_regs, struct cpu_info, guest_cpu_user_regs);
     OFFSET(CPUINFO_verw_sel, struct cpu_info, verw_sel);