libexecinfo fails to build using clang on Darwin

[Xiyue Deng <manphiz%gmail.com@localhost>]

Hi,

When trying to build cmake, libexecinfo fails with the following errors:

----------8<----------
$ bmake install
=> Bootstrap dependency digest>=20010302: found digest-20121220
===> Installing dependencies for libexecinfo-1.1
=> Tool dependency nbpatch-[0-9]*: found nbpatch-20100124
===> Creating toolchain wrappers for libexecinfo-1.1
===> Configuring for libexecinfo-1.1
===> Building for libexecinfo-1.1
--- execinfo.o ---
--- execinfo.so ---
--- execinfo.o ---
clang -pipe -O2   -c execinfo.c
--- execinfo.so ---
clang -pipe -O2   -c -fPIC -DPIC execinfo.c -o execinfo.so
--- stacktraverse.o ---
clang -pipe -O2   -c stacktraverse.c
--- stacktraverse.so ---
clang -pipe -O2   -c -fPIC -DPIC stacktraverse.c -o stacktraverse.so
--- libexecinfo_pic.a ---
building shared object execinfo library
ar -c -q libexecinfo_pic.a `NM=nm lorder stacktraverse.so execinfo.so
| tsort -q`
--- libexecinfo.a ---
building standard execinfo library
ar -c -q libexecinfo.a `NM=nm lorder stacktraverse.o execinfo.o | tsort -q`
--- libexecinfo_pic.a ---
ranlib libexecinfo_pic.a
--- libexecinfo.so.1.0 ---
building shared execinfo library (version 1.0)
clang -shared  -o libexecinfo.so.1.0    --whole-archive
libexecinfo_pic.a --no-whole-archive -lm
--- libexecinfo.a ---
ranlib libexecinfo.a
--- libexecinfo.so.1.0 ---
clang: error: unsupported option '--whole-archive'
clang: error: unsupported option '--no-whole-archive'
*** [libexecinfo.so.1.0] Error code 1

bmake: stopped in /Users/dxy/pkgsrc/devel/libexecinfo/work/libexecinfo-1.1
1 error

bmake: stopped in /Users/dxy/pkgsrc/devel/libexecinfo/work/libexecinfo-1.1
*** Error code 2

Stop.
bmake: stopped in /Users/dxy/pkgsrc/devel/libexecinfo
*** Error code 1

Stop.
bmake: stopped in /Users/dxy/pkgsrc/devel/libexecinfo
----------8<----------

I tried to modify work/.wrapper/tmp/cache and removed args in
"--whole-archive" and "--no-whole-archive" and it seems to pass, but
this is not fixing the issue and I'm not sure whether it is still
producing the correct .a.

Any comment is appreciated.