Initial `dyn` keyword support & `-lang 2026` compiler option (#7172)

fixes: [#7143](https://github.com/shader-slang/slang/issues/7143)
fixes: [#7146](https://github.com/shader-slang/slang/issues/7146)

Goal of PR: 
 * This PR is part of the larger #7115 refactor to how dynamic dispatch works.
 * The first step is to add the `-std <std-revision>` flag.
 * The second step is to provide basic `dyn` keyword support in AST. This does not include `varDecl` support since most of these interactions require `some` keyword support.

Future PR(s) goal:
 * Support `some` keyword in AST. With this we will also implement all varDecl interactions between `dyn` and `some`.
 * Add IR support for `some` and `dyn`.

Breakdown of PR:
 * most of the logic is in `validateDyn.*`. This was done so that in the future when we implement more features we will have an easy time removing/adding restrictions to `dyn` interfaces.

Breaking changes:
* As per spec (https://github.com/shader-slang/spec/pull/14/files), any type conforming to a `dyn` interface errors if member list contains one of the following: opaque type, non copyable type, or unsized type.
* Due to the breaking change, the test `tests\compute\dynamic-dispatch-bindless-texture.slang` is incorrect. This has been fixed.

1 files changed, 14 insertions, 22 deletions

diff --git a/tests/compute/dynamic-dispatch-bindless-texture.slang b/tests/compute/dynamic-dispatch-bindless-texture.slang
index b02ca9686..ec21afeda 100644
--- a/tests/compute/dynamic-dispatch-bindless-texture.slang
+++ b/tests/compute/dynamic-dispatch-bindless-texture.slang
@@ -2,37 +2,29 @@
 //TEST(compute):COMPARE_COMPUTE:-cpu
 //TEST(compute):COMPARE_COMPUTE:-cuda
 
-[anyValueSize(16)]
-interface IInterface
+// Type must be marked `public` to ensure it is visible in the generated DLL.
+
+export struct MyImpl
 {
-    float run();
-}
+    Texture2D tex;
+    float run()
+    {
+        return tex.Load({0, 0, 0}).x;
+    }
+};
 
 //TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=gOutputBuffer
 RWStructuredBuffer<uint> gOutputBuffer;
-//TEST_INPUT: set gCb = new StructuredBuffer<IInterface>{new MyImpl{Texture2D(size=8, content = one), Sampler}}
-StructuredBuffer<IInterface> gCb;
+//TEST_INPUT: set gCb = new StructuredBuffer<MyImpl>{new MyImpl{Texture2D(size=8, content = one)}}
+StructuredBuffer<MyImpl> gCb;
 
 [numthreads(4, 1, 1)]
-void computeMain(int3       dispatchThreadID : SV_DispatchThreadID)
+void computeMain(int3 dispatchThreadID : SV_DispatchThreadID)
 {
     let tid = dispatchThreadID.x;
 
     let inputVal : int = tid;
-    IInterface v0 = gCb.Load(0);
-    SamplerState sampler;
+    MyImpl v0 = gCb.Load(0);
     let outputVal = v0.run();
     gOutputBuffer[tid] = uint(trunc(outputVal));
-}
-
-
-// Type must be marked `public` to ensure it is visible in the generated DLL.
-export struct MyImpl : IInterface
-{
-    Texture2D tex;
-    SamplerState sampler;
-    float run()
-    {
-        return tex.Sample(sampler, float2(0.0, 0.0)).x;
-    }
-};
+}
\ No newline at end of file