Super long path for jom ends up with Error

When compiling and files are deeply nested, build fails. Shortening the path solves the problem.

For exammple

Error: dependent '..\..\..\..\Binary\Product1\windows-x86-msvc2017-amd64\Relea

se\include\Messages\autogen\SystemPerformanceReportMessages.a.h' does not

exist.

But, the file exists and the relative path is correct. Reducing the overall

path length fix the issue.

The full expanded path is

C:\Jenkins\workspace\TestWorkflowKit\trunk\Experimental_windows_x86_msvc2017_a

md64_c\build_release\Product1\Application\SystemPerformanceReport\..\..\..\..\

Binary\Product1\windows-x86-msvc2017-amd64\Release\include\Messages\autogen\Sy

stemPerformanceReportMessages.a.h

This eventually exceeds the 260 character path length restriction in Windows API (ANSI).

If JOM uses unicode function GetFileAttributesExW in FastFileInfo::FastFileInfo() instead of the ANSI version then it solves the problem.

Attached patch solves the problem.