re PR target/9350 (-fomit-frame-pointer does not work for main)

re PR target/9350 (-fomit-frame-pointer does not work for main)

        PR target/9350
        PR target/24374
        * dwarf2out.c (dwarf2out_reg_save_reg): New.
        (dwarf2out_frame_debug_expr): Return after dwarf_handle_frame_unspec.
        * function.c (assign_parms): Use calls.internal_arg_pointer.
        (expand_main_function): Remove FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN
        code.
        * target-def.h (TARGET_INTERNAL_ARG_POINTER): New.
        (TARGET_CALLS): Add it.
        * target.h (struct gcc_target): Add calls.internal_arg_pointer.
        * targhooks.c (default_internal_arg_pointer): New.
        * targhooks.h (default_internal_arg_pointer): Declare.
        * tree.h (dwarf2out_reg_save_reg): Declare.
        * doc/tm.texi (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN): Remove.
        * config/i386/i386.c (dbx_register_map): Add return column.
        (dbx64_register_map, svr4_dbx_register_map): Likewise.
        (TARGET_INTERNAL_ARG_POINTER, ix86_internal_arg_pointer): New.
        (TARGET_DWARF_HANDLE_FRAME_UNSPEC, ix86_dwarf_handle_frame_unspec): New.        (ix86_function_ok_for_sibcall): Disable if force_align_arg_pointer.
        (ix86_save_reg): Save force_align_arg_pointer.
        (ix86_emit_save_regs): Make regno unsigned.
        (ix86_emit_save_regs_using_mov): Likewise.
        (ix86_expand_prologue): Handle force_align_arg_pointer.
        (ix86_expand_epilogue): Likewise.
        * config/i386/i386.h: (dbx_register_map): Update.
        (dbx64_register_map, svr4_dbx_register_map): Update.
        (struct machine_function): Add force_align_arg_pointer.
        * config/i386/i386.md (UNSPEC_REG_SAVE, UNSPEC_DEF_CFA): New.
        (UNSPEC_TP, UNSPEC_TLS_GD, UNSPEC_TLS_LD_BASE): Renumber.
        (TARGET_PUSH_MEMORY peepholes): Disable if RTX_FRAME_RELATED_P.

From-SVN: r106420