Fix missing check for purity on ray tracing builtins

shaders/vulkan/rgen/pure_call.vk.rgen

@@ -0,0 +1,18 @@
+#version 460
+#extension GL_NV_ray_tracing : require
+
+layout(set = 0, binding = 1) uniform accelerationStructureNV as;
+layout(location = 0) rayPayloadNV float payload;
+
+float pure_call(vec2 launchID, vec2 launchSize)
+{
+    vec3 origin = vec3(launchID.x / launchSize.x, launchID.y / launchSize.y, 1.0);
+    vec3 direction = vec3(0.0, 0.0, -1.0);
+    traceNV(as, 0u, 255u, 0u, 1u, 0u, origin, 0.0, direction, 1000.0, 0);
+    return 0.0;
+}
+
+void main()
+{
+    pure_call(vec2(gl_LaunchIDNV.xy), vec2(gl_LaunchSizeNV.xy));
+}

spirv_cross.cpp

@@ -144,6 +144,14 @@ bool Compiler::block_is_pure(const SPIRBlock &block)
 		case OpMemoryBarrier:
 			return false;
 
+		// Ray tracing builtins are impure.
+		case OpReportIntersectionNV:
+		case OpIgnoreIntersectionNV:
+		case OpTerminateRayNV:
+		case OpTraceNV:
+		case OpExecuteCallableNV:
+			return false;
+
 			// OpExtInst is potentially impure depending on extension, but GLSL builtins are at least pure.
 
 		default: