RFR: 8248612: Back quotes and double quotes must not be escaped in: Cannot convert \"$unix_path\" to Windows path

[傅杰]

Hi all,

May I get reviews for this fix?

JBS:    https://bugs.openjdk.java.net/browse/JDK-8248612
Webrev: http://cr.openjdk.java.net/~jiefu/8248612/webrev.00/

Thanks a lot.
Best regards,
Jie