[Bug bootstrap/64023] [5 Regression] r216964 breaks bootstrap on darwin when using gcc as the bootstrap compiler.

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64023

--- Comment #4 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Francois-Xavier Coudert from comment #3)

> Even with that patch, there remains the "silent" issue of not linking
> statically when clang is the system compiler.

The underlying issue is that ld64 will always pick a .dylib over a .a when both
are available.  So pointing at the libstdc++ .libs dir isn't enough - we'll
still link with the dylib.  

AFAIK the only solution available is to mention the full path to the static lib
on the command line.

Since clang does not do this for us (no -static-libstdc++) we'd have to cook up
our own and drive it from some config that determines we are bootstrapping with
clang.  [That might be a useful variable to have anyway]