Implement 8.14-8.19 of OpenGL-GLSL specification

The following PR implements 8.14-8.19 of the [OpenGL-GLSL specification](https://registry.khronos.org/OpenGL/specs/gl/GLSLangSpec.4.60.pdf).

Fully implements all functions and built-in type's, resolves https://github.com/shader-slang/slang/issues/3692 for GLSL & SPRI-V targets.

_Notes:_
Testing Tools:
* Fragment shaders cannot test computational results. Only OpCodes are checked for proper emitting.

Implementation Notes:
* SubpassInput requires an unknown image format.
* SubpassInput is disjoint from TextureType: __SubpassImpl (.slang) & SubpassInputType (Compiler) to reduce code generation required.
* SubpassInput required an additional input layout modifier, input_attachment_index, this was added as a new parameter binding attribute. Since the following qualifiers can overlap with different resources (`layout(input_attachment_index = 0, binding = 0, set = 0)`) input_attachment_index is checked for overlapping resource bindings separately from other qualifiers with `LayoutResourceKind::InputAttachmentIndex`.
* `GLSLInputAttachmentIndexLayoutModifier` was added to enforce function parameters only accepting `in` decorated variables.
* `in` decorated variables needed to have emitting modified to allow directly emitting the variable into function calls if used as a parameter, normally Slang has a "global variable" shadow as a "global parameter" through a copy. This does not work and is solved using `GlobalVariableShadowingGlobalParameterDecoration` to build a relationship of "global variable" to "global parameter", we then resolve this relationship and replace "global variable" uses later in compile.
* `AtomicCounterMemory` memory-constraint requires `OpCapability AtomicStorage`, `AtomicStorage` is invalid for Vulkan targets. glslang outputs for `barrier`, `memoryBarrier`, and `groupMemoryBarrier` `AtomicCounterMemory` as a memory constraint. This compiles as valid SPIR-V for Vulkan since `OpCapability AtomicStorage` is not declared. This behavior of glslang is undefined as per [3.31.Capability of the SPIR-V specification](https://registry.khronos.org/SPIR-V/specs/unified1/SPIRV.html#_capability). We will omit `AtomicCounterMemory` from our barrier calls.

1 files changed, 8 insertions, 0 deletions

diff --git a/source/slang/slang-ir-util.cpp b/source/slang/slang-ir-util.cpp
index e1eb86508..380d1141e 100644
--- a/source/slang/slang-ir-util.cpp
+++ b/source/slang/slang-ir-util.cpp
@@ -411,6 +411,14 @@ void getTypeNameHint(StringBuilder& sb, IRInst* type)
         getTypeNameHint(sb, type->getOperand(0));
         sb << ">";
         break;
+    case kIROp_SubpassInputType:
+        {
+            auto textureType = as<IRSubpassInputType>(type);
+            sb <<"SubpassInput";
+            if(textureType->isMultisample())
+                sb << "MS";
+            break;
+        }
     case kIROp_TextureType:
     case kIROp_GLSLImageType:
         {