CMake: distinguish between file and dir copies by presence of '.' in src path

ANGLE's build requires a file copy. Nema's build requires a dir copy. CMake
uses a different command for each. gn does not distinguish which. We make
a guess that happens to work for these two use cases based on the whether
the base file name of the src contains a '.'


Change-Id: I3503fd9d632abda3f8f952d0eef964019d932bea
Reviewed-on: https://skia-review.googlesource.com/c/188626
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
6 files changed