Bug 1378533 - Make the keys for linked-map-files.json entries absolute paths. r=marco

This patch changes the name of the keys that are in the 'linked-files-map.json' that is produced in the code coverage build and are used to map symbolic links to their source files. The new key names (which are the paths to the symbolic links) are now the entire absolute path to each of the files.

MozReview-Commit-ID: 4x1dfk9h2Ov

--HG--
extra : rebase_source : 7d424bbbf1d026ea67c66b743c8c43ea75185733

python/mozbuild/mozbuild/codecoverage/packager.py

@@ -27,6 +27,7 @@ def describe_install_manifest(manifest, dest_dir):
 
     mapping = {}
     manifest.populate_registry(reg)
+    dest_dir = mozpath.join(buildconfig.topobjdir, dest_dir)
     for dest_file, src in reg:
         if hasattr(src, 'path'):
             dest_path = mozpath.join(dest_dir, dest_file)