patch 8.1.0005: test for :compiler command fails on MS-Windows

Problem:    Test for :compiler command fails on MS-Windows.
Solution:   Ignore difference in path.
diff --git a/src/version.c b/src/version.c
index 32ddbf6..a3eb91a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    5,
+/**/
     4,
 /**/
     3,