Add simple test case for message ids

tests/options/options.expected

@@ -7,4 +7,11 @@ Message5_EnumValue1
 } pb_packed my_packed_struct;
 ! skipped_field
 ! SkippedMessage
+#define PB_MSG_103 Message3
+#define PB_MSG_104 Message4
+#define PB_MSG_105 Message5
+#define OPTIONS_MESSAGES \\
+\s+PB_MSG\(103,[0-9]*,Message3\) \\
+\s+PB_MSG\(104,-1,Message4\) \\
+\s+PB_MSG\(105,[0-9]*,Message5\) \\
 

tests/options/options.proto

@@ -22,12 +22,14 @@ message Message2
 // Field level options
 message Message3
 {
+    option (nanopb_msgopt).msgid = 103;
     required string fieldsize = 1 [(nanopb).max_size = 40];
 }
 
 // Forced callback field
 message Message4
 {
+    option (nanopb_msgopt).msgid = 104;
     required int32 int32_callback = 1 [(nanopb).type = FT_CALLBACK];
 }
 
@@ -47,6 +49,7 @@ message EnumTest
 // Short enum names inside message
 message Message5
 {
+    option (nanopb_msgopt).msgid = 105;
     enum Enum2
     {
        option (nanopb_enumopt).long_names = false;