Revert "Revert removal of F16 literal support for non ARM/SPIR Targets"

This reverts commit a71400342678e0bd321510c0150f7bb30193e49b.

The revert was incomplete. Instead of reverting the changes, just make
HasFloat16 to be true by default.

Change-Id: I8fce8dc3fb584627a7f16c56efbce4073010af9d
4 files changed