"like" shall not crash the script when a non-Str is passed

for example, when you were like `@things[2]` and there weren't enough items.
also, the "hack to deal with failures" was never going to work, as
Failure can't get passed to a Str parameter

lib/Test.pm6

@@ -467,32 +467,46 @@ multi sub can-ok(
 }
 
 multi sub like(
-    Str $got, Regex $expected,
+    $got, Regex $expected,
     $desc = "text matches '$expected.perl()'"
 ) is export {
     $time_after = nqp::time_n;
     $got.defined; # Hack to deal with Failures
-    my $test = $got ~~ $expected;
-    my $ok = proclaim(?$test, $desc);
-    if !$test {
-        _diag "     expected: '$expected.perl()'\n"
-            ~ "     got: '$got'";
+    my $ok;
+    if $got ~~ Str:D {
+        my $test = $got ~~ $expected;
+        $ok = proclaim(?$test, $desc);
+        if !$test {
+            _diag "     expected: '$expected.perl()'\n"
+                ~ "     got: '$got'";
+        }
+    } else {
+        $ok = proclaim(False, $desc);
+        _diag "    expected a Str that matches '$expected.perl()'\n"
+            ~ "    got: '$got.perl()'";
     }
     $time_before = nqp::time_n;
     $ok or ($die_on_fail and die-on-fail) or $ok;
 }
 
 multi sub unlike(
-    Str $got, Regex $expected,
+    $got, Regex $expected,
     $desc = "text does not match '$expected.perl()'"
 ) is export {
     $time_after = nqp::time_n;
     $got.defined; # Hack to deal with Failures
-    my $test = !($got ~~ $expected);
-    my $ok = proclaim(?$test, $desc);
-    if !$test {
-        _diag "     expected: '$expected.perl()'\n"
-            ~ "     got: '$got'";
+    my $ok;
+    if $got ~~ Str:D {
+        my $test = !($got ~~ $expected);
+        $ok = proclaim(?$test, $desc);
+        if !$test {
+            _diag "     expected: '$expected.perl()'\n"
+                ~ "     got: '$got'";
+        }
+    } else {
+        $ok = proclaim(False, $desc);
+        _diag "     expected: a Str that matches '$expected.perl()'\n"
+            ~ "     got: '$got.perl()'";
     }
     $time_before = nqp::time_n;
     $ok or ($die_on_fail and die-on-fail) or $ok;