Fix x86_64-rdos build fail

[Alan Modra]

x86_64-rdos is one of the few x86_64 targets that is 64-bit only and
the x86_64 configure entries don't depend on elf-vxworks.lo.  This
results in undefined references from elfxx-x86.o.

	* configure.ac (elfxx_x86): Define and use.
	* configure: Regenerate.

diff --git a/bfd/configure.ac b/bfd/configure.ac
index 4cd946db00..82aa5b1803 100644
--- a/bfd/configure.ac
+++ b/bfd/configure.ac
@@ -413,6 +413,7 @@ coff="cofflink.lo $coffgen"
 ecoff="ecofflink.lo $coffgen"
 xcoff="xcofflink.lo $coffgen"
 
+elfxx_x86="elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf-vxworks.lo"
 for vec in $selvecs
 do
     target_size=32
@@ -494,16 +495,16 @@ do
     i386_coff_go32_vec)		 tb="$tb coff-go32.lo $coff" ;;
     i386_coff_go32stubbed_vec)	 tb="$tb coff-stgo32.lo $coff" ;;
     i386_coff_lynx_vec)		 tb="$tb cf-i386lynx.lo lynx-core.lo $coff" ;;
-    i386_elf32_vec)		 tb="$tb elf32-i386.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf-vxworks.lo elf32.lo $elf" ;;
-    i386_elf32_fbsd_vec)	 tb="$tb elf32-i386.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf-vxworks.lo elf32.lo $elf" ;;
-    i386_elf32_nacl_vec)	 tb="$tb elf32-i386.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf-vxworks.lo elf32.lo $elf" ;;
-    i386_elf32_sol2_vec)	 tb="$tb elf32-i386.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf-vxworks.lo elf32.lo $elf" ;;
-    i386_elf32_vxworks_vec)	 tb="$tb elf32-i386.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf-vxworks.lo elf32.lo $elf" ;;
+    i386_elf32_vec)		 tb="$tb elf32-i386.lo $elfxx_x86 elf32.lo $elf" ;;
+    i386_elf32_fbsd_vec)	 tb="$tb elf32-i386.lo $elfxx_x86 elf32.lo $elf" ;;
+    i386_elf32_nacl_vec)	 tb="$tb elf32-i386.lo $elfxx_x86 elf32.lo $elf" ;;
+    i386_elf32_sol2_vec)	 tb="$tb elf32-i386.lo $elfxx_x86 elf32.lo $elf" ;;
+    i386_elf32_vxworks_vec)	 tb="$tb elf32-i386.lo $elfxx_x86 elf32.lo $elf" ;;
     i386_mach_o_vec)		 tb="$tb mach-o-i386.lo" ;;
     i386_msdos_vec)		 tb="$tb i386msdos.lo" ;;
     i386_pe_vec)		 tb="$tb pe-i386.lo peigen.lo $coff" ;;
     i386_pei_vec)		 tb="$tb pei-i386.lo peigen.lo $coff" ;;
-    iamcu_elf32_vec)		 tb="$tb elf32-i386.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf-vxworks.lo elf32.lo $elf" ;;
+    iamcu_elf32_vec)		 tb="$tb elf32-i386.lo $elfxx_x86 elf32.lo $elf" ;;
     ia64_elf32_be_vec)		 tb="$tb elf32-ia64.lo elfxx-ia64.lo elf32.lo $elf" ;;
     ia64_elf32_hpux_be_vec)	 tb="$tb elf32-ia64.lo elfxx-ia64.lo elf32.lo $elf" ;;
     ia64_elf64_be_vec)		 tb="$tb elf64-ia64.lo elfxx-ia64.lo elf64.lo $elf"; target_size=64 ;;
@@ -678,13 +679,13 @@ do
     wasm_vec)                    tb="$tb wasm-module.lo" ;;
     wasm32_elf32_vec)            tb="$tb elf32-wasm32.lo elf32.lo $elf" ;;
     x86_64_coff_vec)		 tb="$tb coff-x86_64.lo $coff"; target_size=64 ;;
-    x86_64_elf32_vec)		 tb="$tb elf64-x86-64.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf64.lo elf32.lo $elf"; target_size=64 ;;
-    x86_64_elf32_nacl_vec)	 tb="$tb elf64-x86-64.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf64.lo elf32.lo $elf"; target_size=64 ;;
-    x86_64_elf64_vec)		 tb="$tb elf64-x86-64.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf64.lo $elf"; target_size=64 ;;
-    x86_64_elf64_cloudabi_vec)	 tb="$tb elf64-x86-64.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf64.lo $elf"; target_size=64 ;;
-    x86_64_elf64_fbsd_vec)	 tb="$tb elf64-x86-64.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf64.lo $elf"; target_size=64 ;;
-    x86_64_elf64_nacl_vec)	 tb="$tb elf64-x86-64.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf64.lo $elf"; target_size=64 ;;
-    x86_64_elf64_sol2_vec)	 tb="$tb elf64-x86-64.lo elfxx-x86.lo elf-ifunc.lo elf-nacl.lo elf64.lo $elf"; target_size=64 ;;
+    x86_64_elf32_vec)		 tb="$tb elf64-x86-64.lo $elfxx_x86 elf64.lo elf32.lo $elf"; target_size=64 ;;
+    x86_64_elf32_nacl_vec)	 tb="$tb elf64-x86-64.lo $elfxx_x86 elf64.lo elf32.lo $elf"; target_size=64 ;;
+    x86_64_elf64_vec)		 tb="$tb elf64-x86-64.lo $elfxx_x86 elf64.lo $elf"; target_size=64 ;;
+    x86_64_elf64_cloudabi_vec)	 tb="$tb elf64-x86-64.lo $elfxx_x86 elf64.lo $elf"; target_size=64 ;;
+    x86_64_elf64_fbsd_vec)	 tb="$tb elf64-x86-64.lo $elfxx_x86 elf64.lo $elf"; target_size=64 ;;
+    x86_64_elf64_nacl_vec)	 tb="$tb elf64-x86-64.lo $elfxx_x86 elf64.lo $elf"; target_size=64 ;;
+    x86_64_elf64_sol2_vec)	 tb="$tb elf64-x86-64.lo $elfxx_x86 elf64.lo $elf"; target_size=64 ;;
     x86_64_mach_o_vec)		 tb="$tb mach-o-x86-64.lo" ;;
     x86_64_pe_vec)		 tb="$tb pe-x86_64.lo pex64igen.lo $coff"; target_size=64 ;;
     x86_64_pe_be_vec)		 tb="$tb pe-x86_64.lo pex64igen.lo $coff"; target_size=64 ;;

-- 
Alan Modra
Australia Development Lab, IBM