Add OpKill

include/sirit/sirit.h

@@ -194,6 +194,9 @@ class Module {
     /// Return a value from a function.
     Id OpReturnValue(Id value);
 
+    /// Fragment-shader discard.
+    Id OpKill();
+
     // Debug
 
     /// Assign a name string to a reference.

src/instructions/flow.cpp

@@ -59,4 +59,9 @@ Id Module::OpReturnValue(Id value) {
     return AddCode(std::move(op));
 }
 
+Id Module::OpKill() {
+    AddCapability(spv::Capability::Shader);
+    return AddCode(std::make_unique<Op>(spv::Op::OpKill));
+}
+
 } // namespace Sirit