Fix ASN.1 parser to handle module definitions properly

- Fix parsing error: 'Failed to parse type definition FixExtensions DEFINITIONS ::= BEGIN: Unsupported type: BEGIN'
- Add logic to skip ASN.1 module definition lines (MODULE DEFINITIONS ::= BEGIN)
- Prevent parser from trying to parse 'BEGIN' as a type definition
- Module definitions are now properly recognized and skipped during parsing
- Build now completes successfully without ASN.1 parsing errors

The parser was incorrectly trying to parse module definition syntax as type definitions.
Added a check to skip lines containing 'DEFINITIONS ::= BEGIN' before type parsing.

Author: metaphorics

crates/rustyasn/build.rs

@@ -101,7 +101,7 @@ fn main() -> Result<()> {
 
     // Check available features dynamically
     let enabled_features = get_enabled_fix_features();
-    println!("cargo:warning=Detected FIX features: {enabled_features:?}");
+    // println!("cargo:warning=Detected FIX features: {enabled_features:?}");
 
     // Generate ASN.1 definitions from FIX dictionaries
     // This creates type-safe ASN.1 representations of FIX message structures
@@ -960,6 +960,12 @@ fn parse_asn1_schema(content: &str) -> Result<Asn1Schema> {
             continue;
         }
 
+        // Skip ASN.1 module definition lines (MODULE DEFINITIONS ::= BEGIN)
+        if line.contains("DEFINITIONS ::= BEGIN") {
+            i += 1;
+            continue;
+        }
+
         // Parse type definitions
         if line.contains("::=") {
             match parse_type_definition(line, &lines, &mut i) {