RFR (M) 8191521: handle long relative path specified in -Xbootclasspath/a on windows

[Schmelter, Ralf]

Hi Calvin,


> I'm not sure. Most errors with path begins with "\\\\localhost\\T$\\..."
> A few errors with path begins with "//\\/\\localhost\\T$\\..."
> or "\\\\/\\\\localhost\\\\/\\T$..."

OK, so it is only for UNC path. I will add a check to see if the share is present
and otherwise skip the tests.

Best regards,
Ralf