vcvrack configure uses x86 flags with powerpc, also hardcodes deployment target and C++ runtime

[barracuda156]

Configure is abysmal with this port:

-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - failed
-- Check for working C compiler: /opt/local/bin/gcc-mp-14
-- Check for working C compiler: /opt/local/bin/gcc-mp-14 - broken
CMake Error at /opt/local/share/cmake-3.29/Modules/CMakeTestCCompiler.cmake:67 (message):
  The C compiler

    "/opt/local/bin/gcc-mp-14"

  is not able to compile a simple test program.

  It fails with the following output:

    Change Dir: '/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_audio_vcvrack/vcvrack/work/Rack-1.1.6/dep/glew-2.1.0/build/CMakeFiles/CMakeScratch/TryCompile-rbyRZH'
    
    Run Build Command(s): /opt/local/bin/cmake -E env VERBOSE=1 /opt/local/bin/gmake -f Makefile cmTC_e2543/fast
    gmake[2]: Entering directory '/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_audio_vcvrack/vcvrack/work/Rack-1.1.6/dep/glew-2.1.0/build/CMakeFiles/CMakeScratch/TryCompile-rbyRZH'
    /opt/local/bin/gmake  -f CMakeFiles/cmTC_e2543.dir/build.make CMakeFiles/cmTC_e2543.dir/build
    gmake[3]: Entering directory '/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_audio_vcvrack/vcvrack/work/Rack-1.1.6/dep/glew-2.1.0/build/CMakeFiles/CMakeScratch/TryCompile-rbyRZH'
    Building C object CMakeFiles/cmTC_e2543.dir/testCCompiler.c.o
    /opt/local/bin/gcc-mp-14   -g -O3 -march=nocona -mmacosx-version-min=10.7 -stdlib=libc++  -o CMakeFiles/cmTC_e2543.dir/testCCompiler.c.o -c /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_audio_vcvrack/vcvrack/work/Rack-1.1.6/dep/glew-2.1.0/build/CMakeFiles/CMakeScratch/TryCompile-rbyRZH/testCCompiler.c
    gcc-mp-14: error: unrecognized command-line option '-march=nocona'
    gmake[3]: *** [CMakeFiles/cmTC_e2543.dir/build.make:78: CMakeFiles/cmTC_e2543.dir/testCCompiler.c.o] Error 1
    gmake[3]: Leaving directory '/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_audio_vcvrack/vcvrack/work/Rack-1.1.6/dep/glew-2.1.0/build/CMakeFiles/CMakeScratch/TryCompile-rbyRZH'
    gmake[2]: *** [Makefile:127: cmTC_e2543/fast] Error 2