shader: Fix Phi node types

src/shader_recompiler/frontend/ir/microinstruction.cpp

@@ -275,10 +275,6 @@ void Inst::AddPhiOperand(Block* predecessor, const Value& value) {
     if (!value.IsImmediate()) {
         Use(value);
     }
-    if (Flags<IR::Type>() == IR::Type::Void) {
-        // Set the type of the phi node
-        SetFlags<IR::Type>(value.Type());
-    }
     phi_args.emplace_back(predecessor, value);
 }
 

src/shader_recompiler/ir_opt/ssa_rewrite_pass.cpp

@@ -176,6 +176,8 @@ public:
                 } else if (!sealed_blocks.contains(block)) {
                     // Incomplete CFG
                     IR::Inst* phi{&*block->PrependNewInst(block->begin(), IR::Opcode::Phi)};
+                    phi->SetFlags(IR::TypeOf(UndefOpcode(variable)));
+
                     incomplete_phis[block].insert_or_assign(variable, phi);
                     stack.back().result = IR::Value{&*phi};
                 } else if (const std::span imm_preds{block->ImmediatePredecessors()};
@@ -187,6 +189,8 @@ public:
                 } else {
                     // Break potential cycles with operandless phi
                     IR::Inst* const phi{&*block->PrependNewInst(block->begin(), IR::Opcode::Phi)};
+                    phi->SetFlags(IR::TypeOf(UndefOpcode(variable)));
+
                     WriteVariable(variable, block, IR::Value{phi});
 
                     stack.back().phi = phi;