refactor(compiler): 拆分 oxide_emit 为独立 emit pass crate（依赖倒置）

crates/oxide_emit/src/stmt/exception/throw.rs

@@ -0,0 +1,16 @@
+use crate::{CompileCtx, Emitter};
+use oxide_ir::inst::Inst;
+use oxide_ir::operand::Operand;
+use oxide_bytecode::opcode::OpCode;
+use oxide_parser::Statement;
+
+impl Emitter {
+    pub(crate) fn emit_throw_statement(&self, stmt: &Statement, ctx: &mut CompileCtx) -> Result<Option<u8>, String> {
+        let Statement::ThrowStatement(ts) = stmt else {
+            return Ok(None);
+        };
+        let exc_reg = self.emit_expression(&ts.argument, ctx)?;
+        ctx.inst(Inst::new(OpCode::THROW, Operand::Reg(exc_reg as u32), Operand::None, Operand::None));
+        Ok(None)
+    }
+}