patch 8.2.2179: Vim9: crash when indexing a dict with a number

Problem:    Vim9: crash when indexing a dict with a number.
Solution:   Add ISN_STOREINDEX. (closes #7513)
diff --git a/src/vim9.h b/src/vim9.h
index 26307c2..5ced180 100644
--- a/src/vim9.h
+++ b/src/vim9.h
@@ -55,8 +55,8 @@
     // ISN_STOREOTHER, // pop into other script variable isn_arg.other.
 
     ISN_STORENR,    // store number into local variable isn_arg.storenr.stnr_idx
-    ISN_STORELIST,	// store into list, value/index/variable on stack
-    ISN_STOREDICT,	// store into dictionary, value/index/variable on stack
+    ISN_STOREINDEX,	// store into list or dictionary, type isn_arg.vartype,
+			// value/index/variable on stack
 
     ISN_UNLET,		// unlet variable isn_arg.unlet.ul_name
     ISN_UNLETENV,	// unlet environment variable isn_arg.unlet.ul_name
@@ -304,6 +304,7 @@
 	char_u		    *string;
 	varnumber_T	    number;
 	blob_T		    *blob;
+	vartype_T	    vartype;
 #ifdef FEAT_FLOAT
 	float_T		    fnumber;
 #endif