Use require support_displaced_stepping

This changes some tests to use "require support_displaced_stepping".

gdb/testsuite/gdb.arch/disp-step-insn-reloc.exp

@@ -16,10 +16,7 @@ standard_testfile insn-reloc.c
 set executable $testfile
 set expfile $testfile.exp
 
-if { ![support_displaced_stepping] } {
-    unsupported "displaced stepping"
-    return -1
-}
+require support_displaced_stepping
 
 # Some targets have leading underscores on assembly symbols.
 set additional_flags [gdb_target_symbol_prefix_flags]

gdb/testsuite/gdb.base/async-shell.exp

@@ -15,10 +15,7 @@
 
 standard_testfile
 
-if { ![support_displaced_stepping] } { 
-    unsupported "displaced stepping"
-    return -1
-}
+require support_displaced_stepping
 
 # The testfile uses "run".  The real bug happened only for ![is_remote target].
 if [use_gdb_stub] {

gdb/testsuite/gdb.base/inferior-died.exp

@@ -21,10 +21,7 @@ if {![istarget "*-*-linux*"]} {
     return
 }
 
-if { ![support_displaced_stepping] } {
-    unsupported "inferior-died.exp"
-    return -1
-}
+require support_displaced_stepping
 
 standard_testfile .c
 

gdb/testsuite/gdb.base/moribund-step.exp

@@ -15,10 +15,7 @@
 
 standard_testfile start.c
 
-if { ![support_displaced_stepping] } {
-    unsupported "displaced stepping"
-    return -1
-}
+require support_displaced_stepping
 
 save_vars { GDBFLAGS } {
     set GDBFLAGS "$GDBFLAGS -ex \"set non-stop on\""

gdb/testsuite/gdb.mi/mi-nonstop-exit.exp

@@ -13,10 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-if { ![support_displaced_stepping] } { 
-    unsupported "displaced stepping"
-    return -1
-}
+require support_displaced_stepping
 
 load_lib mi-support.exp
 set MIFLAGS "-i=mi"

gdb/testsuite/gdb.mi/mi-nonstop.exp

@@ -14,10 +14,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
-if { ![support_displaced_stepping] } { 
-    unsupported "displaced stepping"
-    return -1
-}
+require support_displaced_stepping
 
 load_lib mi-support.exp
 set MIFLAGS "-i=mi"

gdb/testsuite/gdb.mi/mi-ns-stale-regcache.exp

@@ -16,10 +16,7 @@
 # Regression test for PR11557.  Make sure we don't end up with a stale
 # register cache just after resuming a thread.
 
-if { ![support_displaced_stepping] } { 
-    unsupported "displaced stepping"
-    return -1
-}
+require support_displaced_stepping
 
 load_lib mi-support.exp
 set MIFLAGS "-i=mi"

gdb/testsuite/gdb.mi/mi-nsintrall.exp

@@ -13,10 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-if { ![support_displaced_stepping] } { 
-    unsupported "displaced stepping"
-    return -1
-}
+require support_displaced_stepping
 
 load_lib mi-support.exp
 set MIFLAGS "-i=mi"

gdb/testsuite/gdb.mi/mi-nsmoribund.exp

@@ -13,10 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-if { ![support_displaced_stepping] } { 
-    unsupported "displaced stepping"
-    return -1
-}
+require support_displaced_stepping
 
 load_lib mi-support.exp
 set MIFLAGS "-i=mi"

gdb/testsuite/gdb.mi/mi-nsthrexec.exp

@@ -18,10 +18,7 @@
 # the main thread doesn't just silently stop at the first internal
 # breakpoint (usually the _dl_debug_state breakpoint).
 
-if { ![support_displaced_stepping] } { 
-    unsupported "displaced stepping"
-    return -1
-}
+require support_displaced_stepping
 
 load_lib mi-support.exp
 set MIFLAGS "-i=mi"

gdb/testsuite/gdb.mi/mi-watch-nonstop.exp

@@ -13,12 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-require !skip_hw_watchpoint_tests
-
-if { ![support_displaced_stepping] } { 
-    unsupported "displaced stepping"
-    return -1
-}
+require !skip_hw_watchpoint_tests support_displaced_stepping
 
 load_lib mi-support.exp
 set MIFLAGS "-i=mi"

gdb/testsuite/gdb.python/py-evthreads.exp

@@ -13,10 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-if { ![support_displaced_stepping] } { 
-    unsupported "displaced stepping"
-    return -1
-}
+require support_displaced_stepping
 
 load_lib gdb-python.exp