[TSan] Don't strip binary/library name until the moment we print it.

This commit changes the place where TSan runtime turns full path
to binary or shared library into its basename
(/usr/foo/mybinary -> mybinary). Instead of doing it as early as possible
(when we obtained the full path from the symbolizer), we now do it as
late as possible (right before printing the error report).

This seems like a right thing to do - stripping to basename is a detail
of report formatting implementation, and should belong there. Also, we
might need the full path at some point - for example, to match the
suppressions.

llvm-svn: 221225