patch 8.0.0724: the message for yanking doesn't indicate the register

Problem:    The message for yanking doesn't indicate the register.
Solution:   Show the register name in the "N lines yanked" message. (Lemonboy,
            closes #1803, closes #1809)
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index 217a295..1606881 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -184,6 +184,7 @@
 	    test_quickfix.res \
 	    test_quotestar.res \
 	    test_retab.res \
+	    test_registers.res \
 	    test_ruby.res \
 	    test_search.res \
 	    test_signs.res \
diff --git a/src/testdir/test_registers.vim b/src/testdir/test_registers.vim
new file mode 100644
index 0000000..912a5c7
--- /dev/null
+++ b/src/testdir/test_registers.vim
@@ -0,0 +1,27 @@
+
+func Test_yank_shows_register()
+    enew
+    set report=0
+    call setline(1, ['foo', 'bar'])
+    " Line-wise
+    exe 'norm! yy'
+    call assert_equal('1 line yanked', v:statusmsg)
+    exe 'norm! "zyy'
+    call assert_equal('1 line yanked into "z', v:statusmsg)
+    exe 'norm! yj'
+    call assert_equal('2 lines yanked', v:statusmsg)
+    exe 'norm! "zyj'
+    call assert_equal('2 lines yanked into "z', v:statusmsg)
+
+    " Block-wise
+    exe "norm! \<C-V>y"
+    call assert_equal('block of 1 line yanked', v:statusmsg)
+    exe "norm! \<C-V>\"zy"
+    call assert_equal('block of 1 line yanked into "z', v:statusmsg)
+    exe "norm! \<C-V>jy"
+    call assert_equal('block of 2 lines yanked', v:statusmsg)
+    exe "norm! \<C-V>j\"zy"
+    call assert_equal('block of 2 lines yanked into "z', v:statusmsg)
+
+    bwipe!
+endfunc