x86/asm/head: Annotate data appropriately

x86/asm/head: Annotate data appropriately

Use the new SYM_DATA, SYM_DATA_START, and SYM_DATA_END in both 32 and 64
bit head_*.S. In the 64-bit version, define also
SYM_DATA_START_PAGE_ALIGNED locally using the new SYM_START. It is used
in the code instead of NEXT_PAGE() which was defined in this file and
had been using the obsolete macro GLOBAL().

Now, the data in the 64-bit object file look sane:
  Value   Size Type    Bind   Vis      Ndx Name
    0000  4096 OBJECT  GLOBAL DEFAULT   15 init_level4_pgt
    1000  4096 OBJECT  GLOBAL DEFAULT   15 level3_kernel_pgt
    2000  2048 OBJECT  GLOBAL DEFAULT   15 level2_kernel_pgt
    3000  4096 OBJECT  GLOBAL DEFAULT   15 level2_fixmap_pgt
    4000  4096 OBJECT  GLOBAL DEFAULT   15 level1_fixmap_pgt
    5000     2 OBJECT  GLOBAL DEFAULT   15 early_gdt_descr
    5002     8 OBJECT  LOCAL  DEFAULT   15 early_gdt_descr_base
    500a     8 OBJECT  GLOBAL DEFAULT   15 phys_base
    0000     8 OBJECT  GLOBAL DEFAULT   17 initial_code
    0008     8 OBJECT  GLOBAL DEFAULT   17 initial_gs
    0010     8 OBJECT  GLOBAL DEFAULT   17 initial_stack
    0000     4 OBJECT  GLOBAL DEFAULT   19 early_recursion_flag
    1000  4096 OBJECT  GLOBAL DEFAULT   19 early_level4_pgt
    2000 0x40000 OBJECT  GLOBAL DEFAULT   19 early_dynamic_pgts
    0000  4096 OBJECT  GLOBAL DEFAULT   22 empty_zero_page

All have correct size and type now.

Note that this also removes implicit 16B alignment previously inserted
by ENTRY:

* initial_code, setup_once_ref, initial_page_table, initial_stack,
  boot_gdt are still aligned
* early_gdt_descr is now properly aligned as was intended before ENTRY
  was added there long time ago
* phys_base's alignment is kept by an explicitly added new alignment

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Cao jin <caoj.fnst@cn.fujitsu.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: linux-arch@vger.kernel.org
Cc: Maran Wilson <maran.wilson@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191011115108.12392-12-jslaby@suse.cz