Test constant and dynamically uniform subgroup shuffle deltas

Test constant and dynamically uniform subgroup shuffle deltas

Add new tests where the second argument to subgroupSuffleUp/Down/Xor is
not fully dynamic but also constant and dynamically uniform, in order to
trigger and test existing compiler optimizations.

In addition, this commit fixes several validation errors in many of the
subgroup tests.

New tests:
dEQP-VK.subgroups.shuffle.*_constant
dEQP-VK.subgroups.shuffle.*_dynamically_uniform

Affected tests:
dEQP-VK.subgroups.*

Components: Vulkan
VK-GL-CTS issue: 3342

Change-Id: I938624ae8b9713262c754dda0112cba0e3f37754