Preparatory patch for "new" x86 personality detection
Preparatory patch for "new" x86 personality detection

* syscall.c: Move PT_FLAGS_COMPAT define to its only user, get_scno().
Rename arm_regs_union's fields to names less likely to collide with
system defines.
(get_regs): Use sizeof(arm_regs_union) instead of sizeof(aarch64_regs).
This should be the same, but htis way it's cleaner.
Remove __X32_SYSCALL_MASK and use __X32_SYSCALL_BIT instead.
Explain 64-bit check in X32 build better.

Signed-off-by: Denys Vlasenko <42afb3a19136e88700e8b77002ea6a5a94c16782@googlemail.com>

lizh06/strace-plus,geekboxzone/mmallow_external_strace,android-ia/platform_external_strace,TeamExodus/external_strace,vrastogi/strace,Distrotech/strace,jamel/strace-plus,Saruta/strace,xin3liang/platform_external_strace,cuviper/strace,DirtyUnicorns/android_external_strace,MonkeyZZZZ/platform_external_strace,Saruta/strace,MonkeyZZZZ/platform_external_strace,lkundrak/strace,lkundrak/strace,vrastogi/strace,geofft/strace,geekboxzone/mmallow_external_strace,DirtyUnicorns/android_external_strace,pombredanne/strace,geofft/strace,DirtyUnicorns/android_external_strace,MonkeyZZZZ/platform_external_strace,xin3liang/platform_external_strace,Yu-AndroidM/android_external_strace,MonkeyZZZZ/platform_external_strace,CyanogenMod/android_external_strace,Saruta/strace,lkundrak/strace,YUPlayGodDev/platform_external_strace,bigzz/strace_android,TeamExodus/external_strace,pombredanne/strace,Distrotech/strace,CyanogenMod/android_external_strace,lkundrak/strace,Infinitive-OS/platform_external_strace,kapdop/android_external_strace,AOSP-YU/platform_external_strace,TeamExodus/external_strace,Yu-AndroidM/android_external_strace,geekboxzone/lollipop_external_strace,vrastogi/strace,gcode-mirror/strace-plus,TeamExodus/external_strace,Distrotech/strace,cuviper/strace,Saruta/strace,pgbovine/strace-plus,gcode-mirror/strace-plus,Yu-AndroidM/android_external_strace,YUPlayGodDev/platform_external_strace,CyanogenMod/android_external_strace,android-ia/platform_external_strace,android-ia/platform_external_strace,pgbovine/strace-plus,bnoordhuis/strace,YUPlayGodDev/platform_external_strace,lizh06/strace-plus,lizh06/strace-plus,bnoordhuis/strace,geofft/strace,jamel/strace-plus,geofft/strace,CyanogenMod/android_external_strace,Infinitive-OS/platform_external_strace,Infinitive-OS/platform_external_strace,Yu-AndroidM/android_external_strace,geekboxzone/lollipop_external_strace,android-ia/platform_external_strace,CyanogenMod/android_external_strace,kapdop/android_external_strace,AOSP-YU/platform_external_strace,geofft/strace,bigzz/strace_android,geekboxzone/lollipop_external_strace,jamel/strace-plus,vrastogi/strace,DirtyUnicorns/android_external_strace,Infinitive-OS/platform_external_strace,android-ia/platform_external_strace,pombredanne/strace,geekboxzone/mmallow_external_strace,jamel/strace-plus,lizh06/strace-plus,AOSP-YU/platform_external_strace,geekboxzone/mmallow_external_strace,geekboxzone/mmallow_external_strace,kapdop/android_external_strace,bigzz/strace_android,kapdop/android_external_strace,pgbovine/strace-plus,cuviper/strace,kapdop/android_external_strace,gcode-mirror/strace-plus,geekboxzone/lollipop_external_strace,YUPlayGodDev/platform_external_strace,bigzz/strace_android,gcode-mirror/strace-plus,lizh06/strace-plus,pgbovine/strace-plus,AOSP-YU/platform_external_strace,bigzz/strace_android,cuviper/strace,Saruta/strace,Infinitive-OS/platform_external_strace,bnoordhuis/strace,Distrotech/strace,YUPlayGodDev/platform_external_strace,Distrotech/strace,jamel/strace-plus,vrastogi/strace,xin3liang/platform_external_strace,xin3liang/platform_external_strace,MonkeyZZZZ/platform_external_strace,cuviper/strace,pgbovine/strace-plus,DirtyUnicorns/android_external_strace,bnoordhuis/strace,TeamExodus/external_strace,pombredanne/strace,AOSP-YU/platform_external_strace,Yu-AndroidM/android_external_strace,geekboxzone/lollipop_external_strace,gcode-mirror/strace-plus