Why do I receive a segmentation fault on opening a file with path received as a parameter with -O3 optimization in C++

I have a main function which calls a function func, with a valid file path as a parameter. I use std::ifstream to open the file. Here's my code:

#include <stdlib.h>
#include <string>
#include <fstream>

int func(std::string filepath)
{
    std::ifstream file(filepath);
    file.close();
    return 0;
}

int main()
{
    std::string filepath = "file.txt";
    func(filepath);
    return 0;
}

On compiling the program with -O3 flag enabled and running it, I receive signal SIGSEGV, Segmentation fault. I use MinGW gcc version 9.2.0

g++ main.cpp -O3
./a

Here's the stack trace I get from gdb

(gdb) bt
#0  0x6fc03a47 in ?? () from C:\Program Files\Git\mingw32\bin\libstdc++-6.dll
#1  0x6fc1b4b2 in ?? () from C:\Program Files\Git\mingw32\bin\libstdc++-6.dll
#2  0x6fc1cb60 in ?? () from C:\Program Files\Git\mingw32\bin\libstdc++-6.dll
#3  0x004014c7 in basic_ifstream (__mode=std::_S_in, __s=..., this=0x22fdd4,
    __in_chrg=<optimized out>, __vtt_parm=<optimized out>)
    at c:/mingw/lib/gcc/mingw32/9.2.0/include/c++/istream:606
#4  _fu4___ZTVSt14basic_ifstreamIcSt11char_traitsIcEE () at main.cpp:7
#5  0x00404317 in main ()
    at c:/mingw/lib/gcc/mingw32/9.2.0/include/c++/bits/char_traits.h:300
#6  0x00401233 in ?? ()
#7  0x004012e5 in mainCRTStartup ()

But it works fine if I compile it with -O3 flag disabled

It also works fine, If open the file from the main function itself

#include <stdlib.h>
#include <string>
#include <fstream>

int main()
{
    std::string filepath = "file.txt";
    std::ifstream file(filepath);
    file.close();
    return 0;
}

The above code works fine even with -O3 flag enabled

How can I make the first program work with -O3 flag enabled?