fix: try/finally 支持 break/continue/return 穿越 finally（completion 机制）

crates/oxide_ir/src/contract.rs

@@ -36,6 +36,8 @@ impl Inst {
             | OpCode::RETURN
             | OpCode::THROW
             | OpCode::JMP
+            | OpCode::BREAK
+            | OpCode::CONTINUE
             | OpCode::JMP_IF_FALSE
             | OpCode::JMP_IF_TRUE
             | OpCode::JMP_IF_NULLISH
@@ -197,6 +199,8 @@ impl Inst {
             }
             // 无条件跳转 / try 标记：b 是 Label，无寄存器
             OpCode::JMP
+            | OpCode::BREAK
+            | OpCode::CONTINUE
             | OpCode::TRY_BEGIN
             | OpCode::TRY_FINALLY_BEGIN
             | OpCode::TRY_END

crates/oxide_ir/src/inst.rs

@@ -218,6 +218,18 @@ impl Inst {
         Self::new(OpCode::JMP, Operand::None, Operand::None, Operand::Label(label))
     }
 
+    /// break 完成：label 指向循环/switch 出口，`crossed` 为逃出的 finally 域数
+    /// （emit 词法计算，运行时据此逐个穿越 finally；0 表示未逃出，不产生完成语义）。
+    /// 编码：rd 槽放 crossed（≤255），label 放 b 槽。
+    pub fn brk(label: LabelId, crossed: u16) -> Self {
+        Self::new(OpCode::BREAK, Operand::Imm(crossed), Operand::None, Operand::Label(label))
+    }
+
+    /// continue 完成：同 break，label 指向循环继续目标。
+    pub fn cont(label: LabelId, crossed: u16) -> Self {
+        Self::new(OpCode::CONTINUE, Operand::Imm(crossed), Operand::None, Operand::Label(label))
+    }
+
     /// 条件寄存器为 false 时跳转。
     pub fn jmp_if_false(cond_reg: u32, label: LabelId) -> Self {
         Self::new(OpCode::JMP_IF_FALSE, Operand::Reg(cond_reg), Operand::None, Operand::Label(label))

crates/oxide_ir/src/lower.rs

@@ -126,6 +126,7 @@ fn encode_inst(inst: &Inst, instrs: &mut Vec<u32>, jumps: &mut Vec<(usize, u32)>
         let start = instrs.len();
         let instr = match inst.op {
             OpCode::JMP => opcode::encode_jmp(0),
+            OpCode::BREAK | OpCode::CONTINUE => opcode::encode(inst.op, cond, 0, 0),
             OpCode::JMP_IF_FALSE => opcode::encode_jmp_if_false(cond, 0),
             OpCode::JMP_IF_TRUE => opcode::encode_jmp_if_true(cond, 0),
             OpCode::JMP_IF_NULLISH => opcode::encode_jmp_if_nullish(cond, 0),
@@ -149,6 +150,8 @@ fn is_jump_op(op: OpCode) -> bool {
     matches!(
         op,
         OpCode::JMP
+            | OpCode::BREAK
+            | OpCode::CONTINUE
             | OpCode::JMP_IF_FALSE
             | OpCode::JMP_IF_TRUE
             | OpCode::JMP_IF_NULLISH