use Rule.outputArtifacts for linker rules

In a subsequent commit we'll extend those to produce optional debug
information artifacts.

Change-Id: I2be47affb6ecebfbea83b96ac1fc1ae7ef97fc65
Reviewed-by: Christian Kandeler <christian.kandeler@theqtcompany.com>
Doc: document cpp.nm{Name|Path}

Change-Id: Ib7f0c5dea07f1cfa5cb19a05f4b929a0c613b330
Reviewed-by: Christian Kandeler <christian.kandeler@theqtcompany.com>