[aarch64] wrong symbol address

[goto]

gcc-aarch64-linux-gnu package in bionic has gcc version 7.2.0.

I have a bug with relocation symbols in this version.
It seems to be fixed in gcc version 7.2.1 (tested with gcc-linaro-7.2.1-2017.11 toolchain). Could you please update the package?

Thank you!

Test case:
``` test.c
struct ld_symbol;
extern struct ld_symbol _test_start, _test_end;

unsigned long long test(void)
{
    unsigned long long test_start = (unsigned long long)&_test_start;
    unsigned long long test_end = (unsigned long long)&_test_end;
    return test_end - test_start;
}
```

``` script.ld
OUTPUT_ARCH(aarch64)
OUTPUT_FORMAT(elf64-littleaarch64)
SECTIONS
{
    _test_start = .;
    .text :
    {
        *(.text)
    }
    _test_end = .;
    . += 0xFFFF0000;
}
```

Compile with:
```
aarch64-linux-gnu-gcc -O1 -c test.c -o test.o
aarch64-linux-gnu-objdump -ld test.o
aarch64-linux-gnu-ld -o test.elf -nostdlib --script script.ld --entry test test.o
aarch64-linux-gnu-objdump -ld test.elf
```

Bad (current):
```
test.o:
test():
   0: 90000001 adrp x1, 0 <_test_end>
   4: f9400021 ldr x1, [x1]
   8: 90000000 adrp x0, 0 <_test_start>
   c: f9400000 ldr x0, [x0]
  10: cb000020 sub x0, x1, x0
  14: d65f03c0 ret

test.elf:
test():
   0: 907fff81 adrp x1, ffff0000 <_test_end+0xfffeffe8>
   4: f9401421 ldr x1, [x1, #40]
   8: 907fff80 adrp x0, ffff0000 <_test_end+0xfffeffe8>
   c: f9401000 ldr x0, [x0, #32]
  10: cb000020 sub x0, x1, x0
  14: d65f03c0 ret
```

Good:
```
test():
   0: 90000001 adrp x1, 0 <_test_end>
   4: 91000021 add x1, x1, #0x0
   8: 90000000 adrp x0, 0 <_test_start>
   c: 91000000 add x0, x0, #0x0
  10: cb000020 sub x0, x1, x0
  14: d65f03c0 ret
```

[Matthias Klose (doko)]

bionic was updated to 7.5.0