Vulkan implicit sampler fixups (#686)

* Fix sampler-less texture functions (#685)

* Fix sampler-less texeture functions

I'm honestly not sure how the original work on this feature in #648 worked at all (probably insufficient testing).

We have these front-end modifiers to indicate that a particular function definition requires a certain GLSL version, or a GLSL extension in order to be used, and they are supposed to be automatically employed by the logic in `emit.cpp` to output `#extension` lines in the output GLSL. However, it turns out that nothing is actually wired up right now, so that adding the modifiers to a declaration is a placebo.

This change propagates the modifiers through as decorations, and then uses them during GLSL code emit, which allows the functions that require `EXT_samplerless_texture_functions` to work.

* fixup: 32-bit warning

* Add serialization support for GLSL extension/version decorations

1 files changed, 16 insertions, 0 deletions

diff --git a/source/slang/ir.cpp b/source/slang/ir.cpp
index 3ba2aa0dd..f05aeabf6 100644
--- a/source/slang/ir.cpp
+++ b/source/slang/ir.cpp
@@ -5344,6 +5344,22 @@ namespace Slang
                 }
                 break;
 
+            case kIRDecorationOp_RequireGLSLExtension:
+                {
+                    auto originalDecoration = (IRRequireGLSLExtensionDecoration*)dd;
+                    auto newDecoration = context->builder->addDecoration<IRRequireGLSLExtensionDecoration>(clonedValue);
+                    newDecoration->extensionName = originalDecoration->extensionName;
+                }
+                break;
+
+            case kIRDecorationOp_RequireGLSLVersion:
+                {
+                    auto originalDecoration = (IRRequireGLSLVersionDecoration*)dd;
+                    auto newDecoration = context->builder->addDecoration<IRRequireGLSLVersionDecoration>(clonedValue);
+                    newDecoration->languageVersion = originalDecoration->languageVersion;
+                }
+                break;
+
             default:
                 // Don't clone any decorations we don't understand.
                 break;