rpcrt4: Return a fault packet if the proc num exceeds the index of the last function available for the interface.

Remove the WINE_RPCFLAG_EXCEPTION hack to pass exception information to 
I_RpcSend.

Native D3DRM puts a branchforward with offset 0 at the beginning of each
execute buffer. With the old code this used to get stuck in an endless
loop. This patch adds a test that shows that such a branchforward
terminates properly.