8287895: Some langtools tests fail on msys2

Reviewed-by: jjg

test/langtools/tools/javac/Paths/Util.sh

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2003, 2022, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -30,7 +30,7 @@
 jimage="${TESTJAVA+${TESTJAVA}/bin/}jimage${EXE_SUFFIX}"
 
 case `uname -s` in
-  Windows*|CYGWIN*)
+  Windows*|CYGWIN*|MSYS*|MINGW*)
     WindowsOnly() { "$@"; }
     UnixOnly() { :; }
     PS=";" ;;