patch 8.2.1375: Vim9: method name with digit not accepted

Problem:    Vim9: method name with digit not accepted.
Solution:   Use eval_isnamec() instead of eval_isnamec1(). (closes #6613)
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index 8be0dea..aa705b2 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -1674,14 +1674,14 @@
   return arg
 enddef
 
-def s:EchoArg(arg: any): string
+def s:Echo4Arg(arg: any): string
   return arg
 enddef
 
 def Test_expr7_call()
   assert_equal('yes', 'yes'->Echo())
   assert_equal('yes', 'yes'
-  			->s:EchoArg())
+  			->s:Echo4Arg())
   assert_equal(1, !range(5)->empty())
   assert_equal([0, 1, 2], --3->range())
 
diff --git a/src/version.c b/src/version.c
index abf2af0..8bc9282 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1375,
+/**/
     1374,
 /**/
     1373,
diff --git a/src/vim9compile.c b/src/vim9compile.c
index e87634b..b3cca58 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -3854,7 +3854,7 @@
 		}
 		if (ASCII_ISALPHA(*p) && p[1] == ':')
 		    p += 2;
-		for ( ; eval_isnamec1(*p); ++p)
+		for ( ; eval_isnamec(*p); ++p)
 		    ;
 		if (*p != '(')
 		{