pe-dll.c (pe_detail_list): arm-pe targets use underscores.

pe-dll.c (pe_detail_list): arm-pe targets use underscores.
(process_def_file): Don't create an export section if there are no exports and
  we're building an exe.
(pe_dll_build_sections): Ditto
(pe_dll_fill_sections): Conditionalize setting abfd->dll true on info->shared

emultempl/pe.em (gld_${EMULATION_NAME}_after_open): If i386pe or armpe, call
  pe_dll_build_section() for both exe's and dll's, not just dll's.  Don't call
  pe_dll_build_section() if link_info.relocateable.
(gld_${EMULATION_NAME}_finish): For all targets except shpe and mipspe, call
  pe_dll_fill_sections() for both exe's and dll's, not just dll's.  Don't call
  pe_dll_fill_sections() if link_info.relocateable.