gcc behavior of init priority of .ctors and .dtors section

Hi,

I'm recently working on https://reviews.freebsd.org/D45194 and got noticed
that gcc behaves weirdly.

A simple source file to demonstrate that.

```
# cat ctors.c

#include <stdio.h>

__attribute__((constructor(101))) void init_101() { puts("init 1"); }
__attribute__((constructor(65535))) void init_65535() { puts("init 3"); }
__attribute__((constructor)) void init() { puts("init 4"); }
__attribute__((constructor(65535))) void init_65535_2() { puts("init 5"); }
__attribute__((constructor(65534))) void init_65534() { puts("init 2"); }

int main() { puts("main"); }

__attribute__((destructor(65534))) void fini_65534() { puts("fini 2"); }
__attribute__((destructor(65535))) void fini_65535() { puts("fini 3"); }
__attribute__((destructor)) void fini() { puts("fini 4"); }
__attribute__((destructor(65535))) void fini_65535_2() { puts("fini 5"); }
__attribute__((destructor(101))) void fini_101() { puts("fini 1"); }

# clang ctors.c && ./a.out
init 1
init 2
init 3
init 4
init 5
main
fini 5
fini 4
fini 3
fini 2
fini 1
```

clang with the option -fno-use-init-array and run will produce the same result, which
is what I expected.

gcc13 from ports
```
# gcc ctors.c && ./a.out
init 1
init 2
init 5
init 4
init 3
main
fini 3
fini 4
fini 5
fini 2
fini 1
```

The above order is not expected. I think clang's one is correct.

Further hacking with readelf shows that clang produces the right order of
section .rela.ctors but gcc does not.

```
# clang -fno-use-init-array -c ctors.c && readelf -r ctors.o | grep 'Relocation section with addend (.rela.ctors)' -A5 > clang.txt
# gcc -c ctors.c && readelf -r ctors.o | grep 'Relocation section with addend (.rela.ctors)' -A5 > gcc.txt
# diff clang.txt gcc.txt
3,5c3,5
< 000000000000 000800000001 R_X86_64_64         0000000000000060 init_65535_2 + 0
< 000000000008 000700000001 R_X86_64_64         0000000000000040 init + 0
< 000000000010 000600000001 R_X86_64_64         0000000000000020 init_65535 + 0
---
> 000000000000 000600000001 R_X86_64_64         0000000000000011 init_65535 + 0
> 000000000008 000700000001 R_X86_64_64         0000000000000022 init + 0
> 000000000010 000800000001 R_X86_64_64         0000000000000033 init_65535_2 + 0
```

The above show clearly gcc produces the wrong order of section `.rela.ctors`.

Is that expected behavior ?

I have not tried Linux version of gcc.


Best regards,
Zhenlei