gdb: update gnulib import

gdb: update gnulib import

This is mostly to get this commit from gnulib:

    e22cd2677a4b7beacbf30b93bb0559f7b89f96ce
    Add ‘extern "C"’ to count-one-bits.h etc.

... which fixes this compilation problem I observed with clang++:

      CXXLD  gdb
    arch/arm-get-next-pcs.o:arm-get-next-pcs.c:function thumb_get_next_pcs_raw(arm_get_next_pcs*): error: undefined reference to 'count_one_bits(unsigned int)'
    <more such undefined references>

I built-tested on GNU/Linux x86-64 (gcc-9 and clang-9) as well as with the
x86_64-w64-mingw32-gcc cross-compiler.

gnulib/ChangeLog:

	* update-gnulib.sh (GNULIB_COMMIT_SHA1): Bump to
	e22cd2677a4b7beacbf30b93bb0559f7b89f96ce.
	* Makefile.in, config.in, configure, import/*: Re-generate.