* ld.h (args_type): Add gc_sections.

    * ld.h (args_type): Add gc_sections.
        * ldgram.y (ldgram_had_keep, KEEP): New.
        (input_section_spec_no_keep): Rename from old input_section_spec.
        (input_section_spec): New.  Recognize KEEP.
        * ldlang.c (wild_section): Handle keep sections.
        (lang_gc_wild_section, lang_gc_wild_file, lang_gc_wild): New.
        (lang_gc_sections_1, lang_gc_sections): New.
        (lang_process): Invoke lang_gc_sections.
        (lang_add_wild): Add keep argument.  Update all callers.
        * ldlang.h (lang_wild_statement_struct): Add keep_sections.
        * ldlex.l (KEEP): Match it.
        * ldmain.c (main): Error on -r and --gc-sections.
        * lexsup.c: Add --gc-sections.

        * scripttempl/elf.sc: Merge .text.* etc sections appropriately.
        Mark startup sections with KEEP.
        * scripttempl/elfppc.sc: Likewise.

        * ld.texinfo: Update for --gc-sections and KEEP.