Define SampleMask as an array

src/shader_recompiler/backend/spirv/emit_spirv_context_get_set.cpp

@@ -473,7 +473,8 @@ void EmitSetFragColor(EmitContext& ctx, u32 index, u32 component, Id value) {
 }
 
 void EmitSetSampleMask(EmitContext& ctx, Id value) {
-    ctx.OpStore(ctx.sample_mask, value);
+    const Id pointer{ctx.OpAccessChain(ctx.output_u32, ctx.sample_mask, ctx.u32_zero_value)};
+    ctx.OpStore(pointer, value);
 }
 
 void EmitSetFragDepth(EmitContext& ctx, Id value) {

src/shader_recompiler/backend/spirv/spirv_emit_context.cpp

@@ -1572,7 +1572,8 @@ void EmitContext::DefineOutputs(const IR::Program& program) {
             Decorate(frag_depth, spv::Decoration::BuiltIn, spv::BuiltIn::FragDepth);
         }
         if (info.stores_sample_mask) {
-            sample_mask = DefineOutput(*this, U32[1], std::nullopt);
+            const Id array_type{TypeArray(U32[1], Const(1U))};
+            sample_mask = DefineOutput(*this, array_type, std::nullopt);
             Decorate(sample_mask, spv::Decoration::BuiltIn, spv::BuiltIn::SampleMask);
         }
         break;