Build failure on ppc-aix (bfd_elf_get_obj_attr_int is undefined)

bfd_uses_spe_extensions should only be used when BFD has been built
with ELF support.  The typical way of checking that in GDB is to use
the HAVE_ELF macro.

gdb/ChangeLog:

        * rs6000-tdep.c (bfd_uses_spe_extensions): Use bfd_elf_get_obj_attr_int
        only if HAVE_ELF is defined.

gdb/ChangeLog

@@ -1,3 +1,8 @@
+2010-11-24  Joel Brobecker  <brobecker@adacore.com>
+
+	* rs6000-tdep.c (bfd_uses_spe_extensions): Use bfd_elf_get_obj_attr_int
+	only if HAVE_ELF is defined.
+
 2010-11-24  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
 	Code cleanup.

gdb/rs6000-tdep.c

@@ -3376,6 +3376,7 @@ bfd_uses_spe_extensions (bfd *abfd)
   if (!abfd)
     return 0;
 
+#ifdef HAVE_ELF
   /* Using Tag_GNU_Power_ABI_Vector here is a bit of a hack, as the user
      could be using the SPE vector abi without actually using any spe
      bits whatsoever.  But it's close enough for now.  */
@@ -3383,6 +3384,7 @@ bfd_uses_spe_extensions (bfd *abfd)
 					 Tag_GNU_Power_ABI_Vector);
   if (vector_abi == 3)
     return 1;
+#endif
 
   sect = bfd_get_section_by_name (abfd, ".PPC.EMB.apuinfo");
   if (!sect)