[libcxx] r282483 - [cmake] Add linker option "-Wl, -z, defs" in standalone build

[Joerg Sonnenberger via cfe-commits]

On Tue, Sep 27, 2016 at 12:15:35PM -0000, Michal Gorny via cfe-commits wrote:
> Author: mgorny
> Date: Tue Sep 27 07:15:35 2016
> New Revision: 282483
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=282483&view=rev
> Log:
> [cmake] Add linker option "-Wl,-z,defs" in standalone build
> 
> Add the "-Wl,-z,defs" linker option that is used to prevent
> underlinking. It is already used by LLVM itself but does not get
> propagated into stand-alone build of libc++. This patch ensures
> that the option is passed in independently of whether libc++ is built
> in-tree or out-of-tree.

Can we turn this into a positive list on platforms where it is known to
work? While I generally find it useful, linker and (GCC) spec stupidity
can easily break it.

Joerg