Merge pull request #5135 from xmake-io/rc2

add rc2

Author: waruqi

xmake/languages/msrc/xmake.lua

@@ -20,7 +20,7 @@
 
 language("msrc")
     add_rules("win.sdk.resource")
-    set_sourcekinds {mrc = ".rc"}
+    set_sourcekinds {mrc = {".rc", ".rc2"}}
     set_sourceflags {mrc = "mrcflags"}
     set_langkinds   {msrc = "mrc"}
     set_mixingkinds("mrc")