elf: Remove the 1-page gap before the RELRO segment

elf: Remove the 1-page gap before the RELRO segment

The existing RELRO scheme may leave a 1-page gap before the RELRO segment
and align the end of the RELRO segment to the page size:

  [18] .eh_frame    PROGBITS    408fa0 008fa0 005e80 00   A  0   0  8
  [19] .init_array  INIT_ARRAY  410de0 00fde0 000008 08  WA  0   0  8
  [20] .fini_array  FINI_ARRAY  410de8 00fde8 000008 08  WA  0   0  8
  [21] .dynamic     DYNAMIC     410df0 00fdf0 000200 10  WA  7   0  8
  [22] .got         PROGBITS    410ff0 00fff0 000010 08  WA  0   0  8
  [23] .got.plt     PROGBITS    411000 010000 000048 08  WA  0   0  8

Instead, we can remove the 1-page gap if the maximum page size >= the
maximum section alignment:

  [18] .eh_frame    PROGBITS    408fa0 008fa0 005e80 00   A  0   0  8
  [19] .init_array  INIT_ARRAY  40fde0 00fde0 000008 08  WA  0   0  8
  [20] .fini_array  FINI_ARRAY  40fde8 00fde8 000008 08  WA  0   0  8
  [21] .dynamic     DYNAMIC     40fdf0 00fdf0 000200 10  WA  7   0  8
  [22] .got         PROGBITS    40fff0 00fff0 000010 08  WA  0   0  8
  [23] .got.plt     PROGBITS    410000 010000 000048 08  WA  0   0  8

Because the end of the RELRO segment is always aligned to the page size
and may not be moved, the RELRO segment size may be increased:

  [ 3] .dynstr      STRTAB      000148 000148 000001 00   A  0   0  1
  [ 4] .eh_frame    PROGBITS    000150 000150 000000 00   A  0   0  8
  [ 5] .init_array  INIT_ARRAY  200150 000150 000010 08  WA  0   0  1
  [ 6] .fini_array  FINI_ARRAY  200160 000160 000010 08  WA  0   0  1
  [ 7] .jcr         PROGBITS    200170 000170 000008 00  WA  0   0  1
  [ 8] .data.rel.ro PROGBITS    200180 000180 000020 00  WA  0   0 16
  [ 9] .dynamic     DYNAMIC     2001a0 0001a0 0001c0 10  WA  3   0  8
  [10] .got         PROGBITS    200360 000360 0002a8 00  WA  0   0  8
  [11] .bss         NOBITS      201000 000608 000840 00  WA  0   0  1

vs the old section layout:

  [ 3] .dynstr      STRTAB      000148 000148 000001 00   A  0   0  1
  [ 4] .eh_frame    PROGBITS    000150 000150 000000 00   A  0   0  8
  [ 5] .init_array  INIT_ARRAY  200b48 000b48 000010 08  WA  0   0  1
  [ 6] .fini_array  FINI_ARRAY  200b58 000b58 000010 08  WA  0   0  1
  [ 7] .jcr         PROGBITS    200b68 000b68 000008 00  WA  0   0  1
  [ 8] .data.rel.ro PROGBITS    200b70 000b70 000020 00  WA  0   0 16
  [ 9] .dynamic     DYNAMIC     200b90 000b90 0001c0 10  WA  3   0  8
  [10] .got         PROGBITS    200d50 000d50 0002a8 00  WA  0   0  8
  [11] .bss         NOBITS      201000 000ff8 000840 00  WA  0   0  1

But there is no 1-page gap.

	PR ld/28743
	* ldlang.c (lang_size_relro_segment_1): Remove the 1-page gap
	before the RELRO segment if the maximum page size >= the maximum
	section alignment.
	* testsuite/ld-i386/pr20830.d: Adjusted.
	* testsuite/ld-s390/gotreloc_64-relro-1.dd: Likewise.
	* testsuite/ld-x86-64/pr14207.d: Likewise.
	* testsuite/ld-x86-64/pr18176.d: Likewise.
	* testsuite/ld-x86-64/pr20830a-now.d: Likewise.
	* testsuite/ld-x86-64/pr20830a.d: Likewise.
	* testsuite/ld-x86-64/pr20830b-now.d: Likewise.
	* testsuite/ld-x86-64/pr20830b.d: Likewise.
	* testsuite/ld-x86-64/pr21038a-now.d: Likewise.
	* testsuite/ld-x86-64/pr21038a.d: Likewise.
	* testsuite/ld-x86-64/pr21038b-now.d: Likewise.
	* testsuite/ld-x86-64/pr21038c-now.d: Likewise.
	* testsuite/ld-x86-64/pr21038c.d: Likewise.