patch 8.2.0170: Coverity warning for ignoring return value

Problem:    Coverity warning for ignoring return value.
Solution:   Check the return value and return if failed.
diff --git a/src/version.c b/src/version.c
index 5560266..c8b576d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -743,6 +743,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    170,
+/**/
     169,
 /**/
     168,
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 9831081..524bcde 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -2917,7 +2917,8 @@
 
 	// evaluate the second expression; any type is accepted
 	*arg = skipwhite(p + 1);
-	compile_expr1(arg, cctx);
+	if (compile_expr1(arg, cctx) == FAIL)
+	    return FAIL;
 
 	// remember the type and drop it
 	--stack->ga_len;
@@ -2942,7 +2943,8 @@
 
 	// evaluate the third expression
 	*arg = skipwhite(p + 1);
-	compile_expr1(arg, cctx);
+	if (compile_expr1(arg, cctx) == FAIL)
+	    return FAIL;
 
 	// If the types differ, the result has a more generic type.
 	type2 = ((type_T **)stack->ga_data)[stack->ga_len - 1];
@@ -3265,6 +3267,7 @@
 	if (*op != '=')
 	{
 	    if (option)
+		// TODO: check the option exists
 		generate_LOAD(cctx, ISN_LOADOPT, 0, name + 1, type);
 	    else if (global)
 		generate_LOAD(cctx, ISN_LOADG, 0, name + 2, type);