ia64 assembler warning breaks ld tests

The "Warning: Explicit stops are ignored in auto mode" results in
failures of a number of run_ld_link_tests because the compiler is run
using -S and then the resulting .s file assembled without suppplying
-x to gas.  Fix that problem by adding -x to ASFLAGS for ia64, and
tweak the binutils link-order test since the source is used in a ld
test too.

ld/
	* testsuite/config/default.exp: Set ASFLAGS to "-x" for ia64.
	Remove unnecessary "global".
binutils/
	* testsuite/binutils-all/link-order.s: Provide explicit stop.
	* testsuite/binutils-all/objcopy.exp: Pass "-x" when building
	link-order test for ia64.

binutils/testsuite/binutils-all/link-order.s

@@ -5,7 +5,7 @@
 foo:
 	.prologue 2, 2
 	.vframe r2
-	mov r2 = r12
+	mov r2 = r12;;
 	.body
 	.restore sp
 	mov r12 = r2

binutils/testsuite/binutils-all/objcopy.exp

@@ -1293,7 +1293,7 @@ proc objcopy_test_elf_common_symbols {} {
 # ia64 specific tests
 if { ([istarget "ia64-*-elf*"]
        || [istarget "ia64-*-linux*"]) } {
-    objcopy_test "ia64 link order" link-order.s object "" ""
+    objcopy_test "ia64 link order" link-order.s object "-x" ""
 }
 
 # ELF specific tests

ld/testsuite/config/default.exp

@@ -185,10 +185,13 @@ if {[istarget mips64*-*-linux*] &&
 }
 
 if { [istarget rx-*-*] } {
-    global ASFLAGS
     set ASFLAGS "-muse-conventional-section-names"
 }
 
+if { [istarget ia64-*-*] } {
+    set ASFLAGS "-x"
+}
+
 # Blackfin ELF targets require selection of an explicit CPU.  Use the sim.
 if {[istarget bfin*-elf*]} {
     append gcc_B_opt " -msim"