MT#20543 Update and enable test suite

- Protect the syntax that we are checking with eval, so that when
  it is not available we can do proper test suite checks instead
  of exiting with compilation errors.
- Remove check for switch feature, which is considered experimental
  with latest perl versions and emits warnings.
- When testing unlink, use a filename that is very unlikely to exist.
- Add libmodule-build-perl to Build-Depends which will be removed from
  perl's core soon.
- Remove dh_auto_test override to enable the test suite.

Change-Id: I458f680d4743ec9025ff68c44b867a7e6398fcd6

debian/control

@@ -5,6 +5,7 @@ Maintainer: Sipwise Development Team <support@sipwise.com>
 Build-Depends:
  debhelper (>= 8),
  libipc-system-simple-perl,
+ libmodule-build-perl,
  libstrictures-perl,
  libtrycatch-perl,
 Standards-Version: 3.9.7

debian/rules

@@ -1,6 +1,3 @@
 #!/usr/bin/make -f
 %:
 	dh $@
-
-override_dh_auto_test:
-	echo "FIXME / TODO - skipping dh_auto_test while it is failing"

t/exports.t

@@ -13,26 +13,23 @@ ok $@, 'strict refs';
 eval { my $foo = 1 + undef };
 ok $@, 'fatal warnings';
 
-ok say(''), 'say syntax is available';
+eval 'say("")';
+ok !$@, 'say syntax is available';
 
-ok state $foobar = 1, 'state syntax is available';
+eval 'state $foobar = 1';
+ok !$@, 'state syntax is available';
 
-eval {
-    given (1) {
-        when (1) {}
-        default {1}
-    }
-};
-ok !$@, 'switch syntax is available';
-
-eval { unlink '/tmp/doesnotexist' };
+eval { unlink '/nonexistent' };
 ok $@, 'autodie is in effect';
 
-try {
-    die bless { fnord => 42 } => 'Foobar';
-} catch (Foobar $e) {
-    ok $e->isa('Foobar'), 'TryCatch works';
-}
+eval q{
+    try {
+        die bless { fnord => 42 } => 'Foobar';
+    } catch (Foobar $e) {
+        $e->isa('Foobar') or die 'TryCatch failed';
+    }
+};
+ok !$@, 'TryCatch is available and works';
 
 ok uc("\xe4") eq "\xc4", 'unicode_strings in effect';