Fix missing declaring class of opaque methods

Author: thomasspriggs

jbmc/src/java_bytecode/java_bytecode_convert_method.cpp

@@ -2207,6 +2207,7 @@ void java_bytecode_convert_methodt::convert_invoke(
     symbol.mode = ID_java;
     assign_parameter_names(
       to_java_method_type(symbol.type), symbol.name, symbol_table);
+    set_declaring_class(symbol, arg0.get(ID_C_class));
 
     debug() << "Generating codet:  new opaque symbol: method '" << symbol.name
             << "'" << eom;

jbmc/unit/java_bytecode/java_bytecode_convert_method/convert_method.cpp

@@ -8,11 +8,14 @@ Author: Diffblue Limited.
 
 #include <testing-utils/use_catch.h>
 
+#include <util/irep.h>
 #include <util/symbol_table.h>
 
 #include <java-testing-utils/load_java_class.h>
 #include <java-testing-utils/require_type.h>
 
+#include <java_bytecode/java_utils.h>
+
 SCENARIO(
   "java_bytecode_convert_bridge_method",
   "[core][java_bytecode][java_bytecode_convert_method]")
@@ -138,6 +141,11 @@ SCENARIO(
       {
         REQUIRE(function_type.get_is_final());
       }
+      THEN("The method should be marked as declared by its class")
+      {
+        REQUIRE(
+          id2string(*declaring_class(function_symbol)) == "java::OpaqueClass");
+      }
     }
   }
 }