patch 8.2.2836: build failure without the +quickfix feature

Problem:    Build failure without the +quickfix feature. (John Marriott)
Solution:   Add #ifdef.
diff --git a/src/vim9execute.c b/src/vim9execute.c
index f260e60..c8586b3 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -1443,11 +1443,14 @@
 		break;
 
 	    case ISN_CEXPR_AUCMD:
+#ifdef FEAT_QUICKFIX
 		if (trigger_cexpr_autocmd(iptr->isn_arg.number) == FAIL)
 		    goto on_error;
+#endif
 		break;
 
 	    case ISN_CEXPR_CORE:
+#ifdef FEAT_QUICKFIX
 		{
 		    exarg_T ea;
 		    int	    res;
@@ -1463,6 +1466,7 @@
 		    if (res == FAIL)
 			goto on_error;
 		}
+#endif
 		break;
 
 	    // execute Ex command from pieces on the stack
@@ -4415,10 +4419,13 @@
 					iptr->isn_arg.number ? " append" : "");
 		break;
 	    case ISN_CEXPR_AUCMD:
+#ifdef FEAT_QUICKFIX
 		smsg("%s%4d CEXPR pre %s", pfx, current,
 				       cexpr_get_auname(iptr->isn_arg.number));
+#endif
 		break;
 	    case ISN_CEXPR_CORE:
+#ifdef FEAT_QUICKFIX
 		{
 		    cexprref_T	    *cer = iptr->isn_arg.cexpr.cexpr_ref;
 
@@ -4427,6 +4434,7 @@
 				       cer->cer_forceit ? "!" : "",
 				       cer->cer_cmdline);
 		}
+#endif
 		break;
 	    case ISN_SUBSTITUTE:
 		{