patch 8.2.3052: Vim9: "legacy call" does not work

Problem:    Vim9: "legacy call" does not work.
Solution:   Do not skip "call" after "legacy". (closes #8454)

src/testdir/test_vim9_func.vim

@@ -2316,6 +2316,23 @@ def Test_legacy_lambda()
   CheckScriptSuccess(lines)
 enddef
 
+def Test_legacy()
+  var lines =<< trim END
+      vim9script
+      func g:LegacyFunction()
+        let g:legacyvar = 1
+      endfunc
+      def Testit()
+        legacy call g:LegacyFunction()
+      enddef
+      Testit()
+      assert_equal(1, g:legacyvar)
+      unlet g:legacyvar
+      delfunc g:LegacyFunction
+  END
+  CheckScriptSuccess(lines)
+enddef
+
 def Test_legacy_errors()
   for cmd in ['if', 'elseif', 'else', 'endif',
               'for', 'endfor', 'continue', 'break',

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3052,
 /**/
     3051,
 /**/

src/vim9compile.c

@@ -9346,8 +9346,10 @@ compile_def_function(
 		break;
 	}
 
-	// Skip ":call" to get to the function name.
+	// Skip ":call" to get to the function name, unless using :legacy
 	p = ea.cmd;
+	if (!(local_cmdmod.cmod_flags & CMOD_LEGACY))
+	{
 	    if (checkforcmd(&ea.cmd, "call", 3))
 	    {
 		if (*ea.cmd == '(')
@@ -9368,6 +9370,7 @@ compile_def_function(
 		if (assign == FAIL)
 		    goto erret;
 	    }
+	}
 
 	/*
 	 * COMMAND after range
@@ -9375,8 +9378,9 @@ compile_def_function(
 	 * "++nr" and "--nr" are eval commands
 	 */
 	cmd = ea.cmd;
-	if (starts_with_colon || !(*cmd == '\''
+	if (!(local_cmdmod.cmod_flags & CMOD_LEGACY)
-			|| (cmd[0] == cmd[1] && (*cmd == '+' || *cmd == '-'))))
+		&& (starts_with_colon || !(*cmd == '\''
+		       || (cmd[0] == cmd[1] && (*cmd == '+' || *cmd == '-')))))
 	{
 	    ea.cmd = skip_range(ea.cmd, TRUE, NULL);
 	    if (ea.cmd > cmd)