PR 55171 4.6 Backport

[Jonathan Liu]

Hello,

Would it be possible to have fix for PR 55171 backported to 4.6 branch?
I am having an issue with the attached test case not working using 
MinGW-w64 GCC 4.6.3 64-bit.

Thanks.

Regards,
Jonathan
class Base {
public:
    virtual ~Base() { }
};

class Derived : public Base
{
public:
    Derived();

private:
    int *num;
};

Derived::Derived() :
    num(new int(123))
{
    int x = 0;
    ++x;
}

int main(int argc, char *argv[])
{
    Derived d;
    return 0;
}

/* GDB stack test case
 * g++ -g test.cpp
 * gdb a.exe
 * (gdb) break 19
 * (gdb) run
 * (gdb) where
 * #0  Derived::Derived (this=0x22fd50) at test.cpp:19
 * #1  0x0000000000000000 in ?? ()
 */