Issue #2065 - Part 5: Fix incorrect inclusion of base file name in destination path for generated FasterMake track files

I'm not sure about what they had in mind when they first wrote this, but this is completely unnecessary. The base name is the file name. This part will break building with `mach faster` once partial filenames with wildcards are included in the package manifest, which became the case when we began supporting the newer MSVC runtime.

This also aligns FasterMake with how RecursiveMake treats wildcard copy directives.

They fixed this in bug 1416465, but it included a conditional that will almost always be true and kept this incorrect joining of the path and base name in the destination path. Since the value for the base name is either empty or contains a partial file name, that conditional effectively does nothing.

python/mozbuild/mozbuild/backend/fastermake.py

@@ -79,7 +79,7 @@ class FasterMakeBackend(CommonBackend, PartialBackend):
                             .add_pattern_symlink(
                                 prefix,
                                 f.full_path[len(prefix):],
-                                mozpath.join(path, f.target_basename))
+                                path)
                     else:
                         self._install_manifests[obj.install_target].add_symlink(
                             f.full_path,