bisect-runner: Only run ./Configure -S when needed

We only need to run it when config.sh has been modified, which only
happens before 5.10.  From v5.23.4-46-g41d7307 onwards ./Configure -S
did not work, until v5.23.5-90-g473edb6, so we need to skip this if we
want to bisect in that region.  (Or we could just skip the die, but we
might as well skip the system call, too.)

diff --git a/Porting/bisect-runner.pl b/Porting/bisect-runner.pl
index 4c1cce9..e7aca65 100755 (executable)
--- a/Porting/bisect-runner.pl
+++ b/Porting/bisect-runner.pl
@@ -1399,10 +1399,9 @@ run_with_options({stdin => '/dev/null', name => 'Configure'},
 patch_SH() unless $options{'all-fixups'};
 apply_fixups($options{'late-fixup'});
 
-if (-f 'config.sh') {
+if (-f 'config.sh' && $major < 10 && $defines{noextensions}) {
     # Emulate noextensions if Configure doesn't support it.
-    fake_noextensions()
-        if $major < 10 && $defines{noextensions};
+    fake_noextensions();
     system_or_die('./Configure -S');
 }