Re-add NV enums for raytracing to prevent build breaks.

Add support for GLSL_EXT_ray_tracing

and SPV_KHR_ray_tracing

This contains the base for ray tracing extensions.

Forbid memoryBarrierAtomicCounter for Vulkan compiles

* Fixes #2005

Allow multiple units in a stage to have push_constants as long
as the blocks match.
Requires #2006 to be fixed to be functional.

* tweaks to #2005 fix after some testing

* add unit tests for push constants across multiple compilation units

For #2005

* update reference output for tests that fail validation

* fix uninitialized result.validationResult

When we use unsized array in shader storage buffer, glslang calculate the offset during delcaring the block, it may lead to incorrect block offsets when its implicit array size changed.

So here is what we do:
1. For GLSL, we add flag explicitOffset in TQualifier, and set it when layout offset is specified explicitly
2. By using this flag we could tell difference as whether it is an explicit offset, and recalculate the block member offset conditionally in OpenGL.

Fixes #2106

* Convert memcmps to strcmps

EXT_debug_printf - make escape sequences better match C/C++

Allow nonuniformEXT() on sampler types

disable escape sequences for #line and #error

This is conservative and still also decorates the loaded value.