initializer_list support in gcc 4.4

[Martin Sebor]

FYI: the head of gcc trunk (future 4.4) implements support for
initializer lists:

$ g++ -dumpversion && g++ -std=c++0x t.cpp && ./a.out
4.4.0
S::S(std::initializer_list<int>): size = 0: { }
S::S(std::initializer_list<int>): size = 4: { 1 2 3 4 }
tmp$ cat t.cpp && g++ -dumpversion && g++ -std=c++0x t.cpp && ./a.out
#include <initializer_list>
#include <stdio.h>

struct S {
    S (std::initializer_list<int> x) {
        printf ("%s: size = %zu: { ", __PRETTY_FUNCTION__, x.size ());
        for (const int *p = x.begin (); p != x.end (); ++p)
            printf ("%d ", *p);
        puts ("}");
    }
};

int main (int argc, char**) {
    S s1 { };
    S s2 ({1, 2, 3, 4});
}
4.4.0
S::S(std::initializer_list<int>): size = 0: { }
S::S(std::initializer_list<int>): size = 4: { 1 2 3 4 }