Perform HasFastProperties check on prototypes when computing call targets in Crankshaft, part 2.

Perform HasFastProperties check on prototypes when computing call targets in Crankshaft, part 2.

The previous fix was for "real" calls, this one is for getters. It is a bit
unfortunate that this has to be fixed twice: We should really break up
Call::ComputeTarget into a predicate and 1 or 2 getters, so code can be reused.

The regression test has been modified a bit to make things more uniform.

Committed: https://code.google.com/p/v8/source/detail?r=12053

[Jakob Kummerow, 2012-07-12 09:29:47]

lgtm