Add emit logic for requirePrelude inst. (#5735)

Author: csyonghe

source/slang/slang-emit-c-like.cpp

@@ -2948,6 +2948,13 @@ void CLikeSourceEmitter::defaultEmitInstExpr(IRInst* inst, const EmitOpInfo& inO
             m_writer->emit(")");
             break;
         }
+    case kIROp_RequirePrelude:
+        {
+            auto preludeTextInst = as<IRStringLit>(inst->getOperand(0));
+            if (preludeTextInst)
+                m_requiredPreludes.add(preludeTextInst);
+            break;
+        }
     case kIROp_RequireGLSLExtension:
         {
             break; // should already have set requirement; case covered for empty intrinsic block

tests/interop/require-prelude.slang

@@ -0,0 +1,11 @@
+//TEST:SIMPLE(filecheck=CHECK): -target glsl -entry computeMain -stage compute
+//TEST:SIMPLE(filecheck=CHECK): -target wgsl -entry computeMain -stage compute
+//TEST:SIMPLE(filecheck=CHECK): -target metal
+
+// CHECK: #[compute]
+
+[numthreads(1,1,1)]
+void computeMain()
+{
+    __requirePrelude(R"(#[compute])");
+}