SPIR-V 1.4 is coupled with Vulkan 1.2 to introduce a core extension
that exposes float controls and new OpExecutionMode arguments for
controlling floating point behavior. Those Execution Modes are only
legal if the implementation says it supports them in the
FloatControlsProperties struct. SPIR-V 1.4 also adds some operands
and a few new opcodes.

This version update tells SPIR-V tools to allow behavior created to
support version 1.4, like uniform buffer standard packing. It also
exposes the Vulkan extension for SPIR-V 1.4.

Bug: b/173046235
Tests: dEQP-VK.*
Change-Id: I4bb387fd7ba4695babff3edbcaabca583c4fdde1
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/50228Tested-by: Sean Risser <srisser@google.com>
Commit-Queue: Sean Risser <srisser@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>