Fix .d generation in Chrome OS.

Chrome OS toolchain generates "-:" instead of "-.o:" when reading the
source from stdin "-". This patch makes the code handle both cases and
fixes some missing quotes.

Bug: chromium:609385
Bug: 27954979
TEST=FEATURES=test emerge-link chromeos-minijail

Change-Id: I88b03d1c080308560f71b4d3f2e3b1522c8900e9
2 files changed