TryCatch and the Goto outside problems

[dadhi]

See #438 for the context

When the last statement in a TryCatch block is a goto and the label is on the outside, we encounter an System.InvalidProgramException: Common Language Runtime detected an invalid program. error. We haven’t been able to find a reliable workaround for this yet.

// FEC throws `System.InvalidProgramException: Common Language Runtime detected an invalid program.`
var label = Label( "label" );
var variable = Variable( typeof( int ), "variable" );

var block = Block(
    [variable],
    TryCatch(
        Block(
            Assign( variable, Constant( 5 ) ),
            Goto( label )
        ),
        Catch(
            typeof( Exception ),
            Block(
                typeof( void ),
                Assign( variable, Constant( 10 ) )
            )
        )
    ),
    Label( label ),
    variable
);

var lambda = Lambda<Func<int>>( block );

Additionally we also found that when the label is moved into the same scope as the goto we get System.ArgumentException: Bad label content in ILGenerator.

// FEC throws `System.ArgumentException: Bad label content in ILGenerator.`
var label = Label( "label" );
var variable = Parameter( typeof( int ) );
var exceptionParam = Parameter( typeof( Exception ), "ex" );

var block = Block(
    [variable],
    TryCatch(
        Block(
            Goto( label ),
            Throw( Constant( new Exception( "Exception" ) ) ),
            Label( label ),
            Assign( variable, Constant( 2 ) )
        ),
        Catch( exceptionParam, Assign( variable, Constant( 50 ) ) )
    ),
    variable
);

var lambda = Lambda<Func<int>>( block );
var compiledLambda = lambda.CompileFast();