[mingw-w64-x86_64-gcc] weak handle_contract_violation from libstdc++exp.a is not extracted during linking

[Alias10294]

Description / Steps to reproduce the issue

The default C++26 contract violation handler provided by
libstdc++exp.a is not resolved when linking a program with
-fcontracts on MINGW64.

The archive contains the expected symbol, but it is defined as a weak
symbol and does not appear to be extracted automatically by the linker.

Steps to reproduce

1. Create a code file that uses the C++26 contracts such as this code

# bug_repro.cpp
void f(int value)
  pre(value > 0)
{ }

int main()
{ f(1); }

2. attempt to compile it using c++ -std=c++26 -fcontracts bug_repro.cpp -o bug_repro.exe

Environment

• C++ version : c++.exe (Rev5, Built by MSYS2 project) 16.1.0
• ld version : GNU ld (GNU Binutils) 2.46.1
• mingw-w64-x86_64-gcc version : mingw-w64-x86_64-gcc 16.1.0-5
• mingw-w64-x86_64-gcc-libs version : mingw-w64-x86_64-gcc-libs 16.1.0-5
• mingw-w64-x86_64-binutils version : mingw-w64-x86_64-binutils 2.46.1-2

Expected behavior

The program should compile without any kind of error.

Actual behavior

The compiler output this error twice (for the proposed bug_repro.cpp):

undefined reference to `handle_contract_violation(std::contracts::contract_violation const&)'

Verification

• I have verified that my MSYS2 is up-to-date before submitting the report (see https://www.msys2.org/docs/updating/)

Windows Version

MINGW64_NT-10.0-26200

MINGW environments affected

• MINGW64
• MINGW32
• UCRT64
• CLANG64
• CLANGARM64

Are you willing to submit a PR?

No response

[Peter0x44]

This is a binutils issue. I fixed it upstream.
Same as skeeto/w64devkit#393