Cutover various gen*.c files to using system.h:

Cutover various gen*.c files to using system.h:

        * Makefile.in (genconfig.o, genflags.o, gencodes.o, genemit.o,
        genopinit.o, genrecog.o, genextract.o, genpeep.o, genattr.o,
        genattrtab.o, genoutput.o): Depend on system.h.
        * genattr.c: Include system.h.  Add arguments to various function
        prototypes.  Remove redundant prototype of read_rtx().
        * genattrtab.c: Likewise.
        * gencodes.c: Likewise.
        * genconfig.c: Likewise.
        * genemit.c: Likewise.
        * genextract.c: Likewise.
        * genflags.c: Likewise.
        * genopinit.c: Likewise.
        * genoutput.c: Likewise.
        * genpeep.c: Likewise.
        * genrecog.c: Likewise.

From-SVN: r18794