patch 8.1.0978: blob not tested with Perl

Problem:    Blob not tested with Perl.
Solution:   Add more test coverage.  Fixes a crash. (Dominique Pelle,
            closes #4037)
diff --git a/src/testdir/test_perl.vim b/src/testdir/test_perl.vim
index 03c5fa0..e24c04f 100644
--- a/src/testdir/test_perl.vim
+++ b/src/testdir/test_perl.vim
@@ -29,6 +29,13 @@
   call assert_equal('abc/def/', getline('$'))
 endfunc
 
+funct Test_VIM_Blob()
+  call assert_equal('0z',         perleval('VIM::Blob("")'))
+  call assert_equal('0z31326162', perleval('VIM::Blob("12ab")'))
+  call assert_equal('0z00010203', perleval('VIM::Blob("\x00\x01\x02\x03")'))
+  call assert_equal('0z8081FEFF', perleval('VIM::Blob("\x80\x81\xfe\xff")'))
+endfunc
+
 func Test_buffer_Delete()
   new
   call setline(1, ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'])