* toplev.c (init_asm_output): Add explicit 'b' to mode when
        opening asm_out_file.
        * c-pch.c (c_common_write_pch): Remove unnecessary fflush before
        reading asm_out_file. Replace fflush after reading asm_out_file
        with fseek.
        * hosthooks-def.h (HOST_HOOKS_GT_PCH_ALLOC_GRANULARITY): Define
        default and add to HOST_HOOKS_INITIALIZER.
        * hosthooks.h (gt_pch_alloc_granularity): Declare hook function.
        * ggc-common.c (default_gt_pch_alloc_granularity): New function.
        (gt_pch_save): Use host_hooks.gt_pch_alloc_granularity
        to set mmi.offset padding.
         * config.gcc (i[34567]86-*-mingw32*): Set target_gtfiles to
        $(srcdir)/config/i386/winnt.c.
        (i[34567]86-*-pe | i[34567]86-*-cygwin*): Likewise.
        (i[34567]86-*-uwin*): Likewise.
        *i[34567]86-*-interix3*): Likewise.
        * config.host (i[34567]86-*-mingw32*): Set out_host_hook_obj.
        * config/i386/host-mingw32.c: New file.
        * config/i386/x-mingw32: Add rule for host-mingw32.o.
        * config/i386/winnt.c: (struct extern_list) Tag as GTY.
        (extern_head): Likewise.
        (struct export_list) Likewise.
        (export_head): Likewise.
        (i386_pe_record_external_function): Use ggc_alloc.
        (i386_pe_record_exported_symbol): Likewise.
        Include "gt-winnt.h" at end.
        * doc/hostconfig.texi: Document
	HOST_HOOKS_GT_PCH_ALLOC_GRANULARITY.

From-SVN: r82643