patch 9.1.1065: no digraph for "Approaches the limit"

Problem:  no digraph for "Approaches the limit"
Solution: Add the digraph using .= (Hans Ginzel)

Add digraph Approaches the Limit

≐ U+2250 https://www.fileformat.info/info/unicode/char/2250/index.htm

closes: #16508

Signed-off-by: Hans Ginzel <hans@matfyz.cz>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/digraph.c

@@ -997,6 +997,7 @@ static digr_T digraphdefault[] = {
 	{'?', '=', 0x2245},
 	{'?', '2', 0x2248},
 	{'=', '?', 0x224c},
+	{'.', '=', 0x2250},
 	{'H', 'I', 0x2253},
 	{'!', '=', 0x2260},
 	{'=', '3', 0x2261},

src/testdir/test_digraph.vim

@@ -40,6 +40,9 @@ func Test_digraphs()
   " Quadruple prime
   call Put_Dig("'4")
   call assert_equal("⁗", getline('.'))
+  " APPROACHES THE LIMIT
+  call Put_Dig(".=")
+  call assert_equal("≐", getline('.'))
   " Not a digraph
   call Put_Dig("a\<bs>")
   call Put_Dig("\<bs>a")

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1065,
 /**/
     1064,
 /**/