[libcxx] Make __wrap_iter work with gcc.
he following snippet doesn't build when using gcc and libc++:
#include <string>
void f(const std::string& s) { s.begin(); }
#include <vector>
void AppendTo(const std::vector<char>& v) { v.begin(); }
The problem is that __wrap_iter has a private constructor. It lists vector<>
and basic_string<> as friends, but gcc seems to ignore this for vector<> for
some reason. Declaring vector before the friend declaration in __wrap_iter is
enough to work around this problem, so do that. With this patch, I'm able to
build chromium/android with libc++. Without it, two translation units fail to
build. (iosfwd already provides a forward declaration of basic_string.)
As far as I can tell, this is due to a gcc bug, which I filed as
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64816.
Fixes PR22355.
http://reviews.llvm.org/D7201
llvm-svn: 227226