fixed 'optional configure' code to not genrate libc++ code when its not installed (kludge to look in hardwired place but good enuf for now)
fixed 'optional configure' code to not genrate libc++ code when its not installed (kludge to look in hardwired place but good enuf for now)

SophistSolutions/Stroika,SophistSolutions/Stroika,SophistSolutions/Stroika,SophistSolutions/Stroika,SophistSolutions/Stroika