Add new BSS_PLT variable for when .plt need not be contained in
the file. Move _etext so that it is also after .fini, and provide
both etext and _etext with a leading underscore. Mark the start
and end of .sbss.
being .rel.sdata, .rel.sdata.*, .rel.gnu.linkonce.s*.
(.rela.sdata): Likewise for .rela.sdata.* and .rela.gnu.linkonce.s*.
(.rel.sbss): Make like .rel.bss.
(.rela.sbss): Make like .rel.bss.
(.sdata): Don't include .gnu.linkonce.s.* or .sdata.* when
ld -r.
(.sbss): Do the same things as for .bss: include SDATA_START_SYMBOLS,
.dynsbss.
unwinders so that they are closer to the text section.
(OTHER_BSS_SECTIONS): Define.
(EXECUTABLE_SYMBOLS): Provide __SYSTEM_ID and _FPU_STATUS.
(INIT_START, INIT_END): Define.
(FINI_START, FINI_END): Define.
* scripttempl/elf.sc: Add support for INIT_START, INIT_END,
FINI_START, FINI_END and OTHER_BSS_SECTIONS.