Mac version of upcxx-meta no longer handles CXXFLAGS

[Scott Baden]

$UPCXX_INSTALL/bin/upcxx-meta CXXFLAGS Error: parameter passed to upcxx-meta must be one of PPFLAGS LIBFLAGS LDFLAGS CXX CC GASNET_CONDUIT GASNET_INSTALL $UPCXX_INSTALL/bin/upcxx-meta Error: parameter passed to upcxx-meta must be one of PPFLAGS LIBFLAGS LDFLAGS CXX CC GASNET_CONDUIT GASNET_INSTALL On Cori

$UPCXX_INSTALL/bin/upcxx-meta CXXFLAGS -std=c++11 -O2 -Wno-format -Wno-unused -Wunused-result -Wno-unused-parameter -Wno-address edison03 b/baden% $UPCXX_INSTALL/bin/upcxx-meta Error: parameter passed to upcxx-meta must be one of CPPFLAGS PPFLAGS CXXFLAGS LIBS LIBFLAGS LDFLAGS CXX CC GASNET_CONDUIT GASNET_INSTALL

[Dan Bonachea]

Duplicate of #160.