More cleanups...several ports are major redundancies of other ports

src/backend/port/Makefile.in

src/backend/port/getrusage.c

src/backend/port/hpux/port.c

src/backend/port/i386_solaris/port.c

src/backend/port/rusagestub.h

src/backend/port/sco/Makefile

src/backend/port/sco/port.c

src/backend/port/sparc_solaris/Makefile

src/backend/port/sparc_solaris/port.c

src/backend/port/srandom.c

src/backend/port/strcasecmp.c

src/backend/port/svr4/Makefile