recompiler: emit a label right after s_branch to prevent dead code interferrence (#1785)

Author: roamic

src/shader_recompiler/frontend/control_flow_graph.cpp

@@ -80,6 +80,8 @@ void CFG::EmitLabels() {
         if (inst.IsUnconditionalBranch()) {
             const u32 target = inst.BranchTarget(pc);
             AddLabel(target);
+            // Emit this label so that the block ends with s_branch instruction
+            AddLabel(pc + inst.length);
         } else if (inst.IsConditionalBranch()) {
             const u32 true_label = inst.BranchTarget(pc);
             const u32 false_label = pc + inst.length;