Enable ifunc attribute by default for SPARC GNU/Linux.

Similar to other architectures with IFUNC binutils/glibc support, this
patch enables the ifunc attribute for SPARC GNU/Linux.  This is needed
for building glibc with the current checks on IFUNC resolver types
(and use of the attribute in glibc rather than manually created IFUNCs
is beneficial anyway because it results in better debug info).

Tested compilation of glibc with build-many-glibcs.py.  I have not run
the GCC tests for SPARC.

	* config.gcc (default_gnu_indirect_function): Default to yes for
	sparc*-*-linux* with glibc.

From-SVN: r253253

gcc/ChangeLog

 2017-09-28  Joseph Myers  <joseph@codesourcery.com>
 
+	* config.gcc (default_gnu_indirect_function): Default to yes for
+	sparc*-*-linux* with glibc.
+
+2017-09-28  Joseph Myers  <joseph@codesourcery.com>
+
 	* config/aarch64/aarch64.c (aarch64_elf_asm_constructor)
 	(aarch64_elf_asm_destructor): Pass SECTION_NOTYPE to get_section
 	when creating .init_array and .fini_array sections with priority

gcc/config.gcc

@@ -3102,7 +3102,7 @@ case ${target} in
         ;;
 *-*-linux*)
 	case ${target} in
-	aarch64*-* | i[34567]86-* | powerpc*-* | s390*-* | x86_64-*)
+	aarch64*-* | i[34567]86-* | powerpc*-* | s390*-* | sparc*-* | x86_64-*)
 		default_gnu_indirect_function=yes
 		;;
 	esac