patch 8.2.2842: Vim9: skip argument to searchpair() is not compiled

Problem:    Vim9: skip argument to searchpair() is not compiled.
Solution:   Add VAR_INSTR.
diff --git a/src/structs.h b/src/structs.h
index 8da7c7b..9861bb6 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1371,6 +1371,7 @@
 typedef struct channel_S channel_T;
 typedef struct cctx_S cctx_T;
 typedef struct ectx_S ectx_T;
+typedef struct instr_S instr_T;
 
 typedef enum
 {
@@ -1389,6 +1390,7 @@
     VAR_DICT,		// "v_dict" is used
     VAR_JOB,		// "v_job" is used
     VAR_CHANNEL,	// "v_channel" is used
+    VAR_INSTR,		// "v_instr" is used
 } vartype_T;
 
 // A type specification.
@@ -1429,6 +1431,7 @@
 	channel_T	*v_channel;	// channel value (can be NULL!)
 #endif
 	blob_T		*v_blob;	// blob value (can be NULL!)
+	instr_T		*v_instr;	// instructions to execute
     }		vval;
 } typval_T;