Spvc tests: Assemble explicitly for Vulkan1.1 env (#615)
Spvc tests: Assemble explicitly for Vulkan1.1 env (#615)

By default, SPIRV-Tools will assemble for the latest supported
version of SPIR-V.  With SPIR-V 1.4 arriving, that will generally
make modules which are not consumable by Vuklan 1.1.  So update
the Spvc tests to explicitly assemble for Vulkan 1.1.
antiagainst/shaderc,dneto0/shaderc,antiagainst/shaderc,dneto0/shaderc,dneto0/shaderc,antiagainst/shaderc,antiagainst/shaderc,dneto0/shaderc