Update copyright in libgcc.

libgcc/ChangeLog

libgcc/Makefile.in

libgcc/config.host

libgcc/config/aarch64/crti.S

libgcc/config/aarch64/crtn.S

libgcc/config/aarch64/linux-unwind.h

libgcc/config/aarch64/sfp-exceptions.c

libgcc/config/aarch64/sfp-machine.h

libgcc/config/aarch64/sync-cache.c

libgcc/config/aarch64/t-aarch64

libgcc/config/alpha/crtfastmath.c

libgcc/config/alpha/libgcc-alpha-ldbl.ver

libgcc/config/alpha/linux-unwind.h

libgcc/config/alpha/qrnnd.S

libgcc/config/alpha/vms-dwarf2.S

libgcc/config/alpha/vms-dwarf2eh.S

libgcc/config/alpha/vms-gcc_shell_handler.c

libgcc/config/alpha/vms-unwind.h

libgcc/config/arm/bpabi-lib.h

libgcc/config/arm/bpabi-v6m.S