Avoid calling files.stat(source) in symlinkWithOverwrite.
Avoid calling files.stat(source) in symlinkWithOverwrite.

This was dangerous because source is often a path relative to the old
target file, whereas files.stat was interpreting source as a path relative
to process.cwd().

Fixes #9203.

Hansoft/meteor,Hansoft/meteor,Hansoft/meteor,Hansoft/meteor,Hansoft/meteor,Hansoft/meteor,Hansoft/meteor