Add default descriptorset decoration for acceleration structure (#2257)

variables.
diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index e41bb5d..92cce81 100644
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -1292,7 +1292,8 @@
     // basically samplerXXX/subpass/sampler/texture are all included
     // if they are the global-scope-class, not the function parameter
     // (or local, if they ever exist) class.
-    if (type.getBasicType() == glslang::EbtSampler)
+    if (type.getBasicType() == glslang::EbtSampler ||
+        type.getBasicType() == glslang::EbtAccStruct)
         return type.getQualifier().isUniformOrBuffer();
 
     // None of the above.