* configure.in (in_tree_gas): Find out here whether GAS is ELF,
set in_tree_gas_is_elf accordingly.
(in_tree_ld): Find out whether LD emulation is ELF, set
in_tree_ld_is_elf accordingly.
(gcc_cv_as_subsections, gcc_cv_as_hidden, gcc_cv_as_leb128)
(gcc_cv_as_eh_frame, gcc_cv_as_shf_merge)
(gcc_cv_as_dwarf2_debug_line, gcc_cv_as_gdwarf2_flag)
(gcc_cv_as_gstabs_flag): Use $in_tree_gas_is_elf instead of
grepping gas/Makefile.
(gcc_cv_ld_ro_rw_mix, gcc_cv_ld_eh_frame_hdr, gcc_cv_ld_pie): Use
$in_tree_ld_is_elf instead of grepping ld/Makefile.
* configure: Regenerate.
From-SVN: r68356
