[Java.Interop] Ignore swallowing exceptions for optional assembly load (#235)

The method:

	System.Void Java.Interop.JniRuntime::SetMarshalMemberBuilder(Java.Interop.JniRuntime/CreationOptions)

tries to load optional Export assembly. We don't care about the
problem loading it and presume it is missing when exception is 
caught.

Author: radekdoulik

gendarme-ignore.txt

@@ -224,6 +224,8 @@ R: Gendarme.Rules.Design.Generic.DoNotExposeNestedGenericSignaturesRule
 M: System.Linq.Expressions.Expression`1<System.Func`4<System.Reflection.ConstructorInfo,Java.Interop.JniObjectReference,System.Object[],System.Object>> Java.Interop.JniRuntime/JniMarshalMemberBuilder::CreateConstructActivationPeerExpression(System.Reflection.ConstructorInfo)
 
 R: Gendarme.Rules.Exceptions.DoNotSwallowErrorsCatchingNonSpecificExceptionsRule
+# the *.Export assemblies are optional, so we don't care when they cannot be loaded (they are presumably missing)
+M: System.Void Java.Interop.JniRuntime::SetMarshalMemberBuilder(Java.Interop.JniRuntime/CreationOptions)
 M: System.Reflection.Assembly Java.Interop.JniRuntime/JniTypeManager::TryLoadAssembly(System.Reflection.AssemblyName)
 # The exception is transitioned to Jni
 M:System.Void Java.Interop.ManagedPeer::Construct(System.IntPtr,System.IntPtr,System.IntPtr,System.IntPtr,System.IntPtr,System.IntPtr)

src/Java.Interop/Java.Interop/JniRuntime.JniMarshalMemberBuilder.cs

@@ -32,7 +32,8 @@ partial void SetMarshalMemberBuilder (CreationOptions options)
 			Assembly jie;
 			try {
 				jie = Assembly.Load (new AssemblyName ("Java.Interop.Export"));
-			} catch (Exception) {
+			} catch (Exception e) {
+				System.Diagnostics.Debug.WriteLine ($"Java.Interop.Export assembly was not loaded: {e}");
 				return;
 			}
 			var t   = jie.GetType ("Java.Interop.MarshalMemberBuilder");