codegen.c: add peephole optimization for `OP_LOADI32` before `OP_MOVE`.

mrbgems/mruby-compiler/core/codegen.c

@@ -488,7 +488,7 @@ gen_move(codegen_scope *s, uint16_t dst, uint16_t src, int nopeep)
       s->pc = s->lastpc;
       genop_2(s, data.insn, dst, data.b);
       break;
-    case OP_GETUPVAR:
+    case OP_GETUPVAR: case OP_LOADI32:
       if (nopeep || data.a != src || data.a < s->nlocals) goto normal;
       s->pc = s->lastpc;
       genop_3(s, data.insn, dst, data.b, data.c);