A key tool in reverse engineering is a good disassembler, so to ensure that a disassembler is performing properly, are there any good test suites available for use to test the correctness of a disassembler?  Are these architecture specific, or can they be configured to work across multiple object architectures?  A good test should include checking the more obscure architecture instructions and malformed portable execution files.Here is one specifically for i86 that I have seen.  Are there any that are modular across architectures?
Are there any open source test suites for testing how well a disassembler performs?
tools;disassembly
There is a paper called N-version Disassembly: Differential Testing of x86 Disassemblers (PDF) by  Roberto Paleari, Lorenzo Martignoni, Giampaolo Fresi Roglia, and Danilo Bruschi which compares several x86 disassemblers in a formal fashion.To quote the papers abstract:The output of a disassembler is used for many different purposes  (e.g., debugging and reverse engineering). Therefore, disassemblers  represent the rst link of a long chain of stages on which any  high-level analysis of machine code depends upon. In this paper we  demonstrate that many disassemblers fail to decode certain  instructions and thus that the rst link of the chain is very weak. We  present a methodology, called N-version disassembly, to verify the  correctness of disassemblers, based on differential analysisNot sure if this is slightly off topic to your question but may be of interest to you.