My recent change to linux-dp.exp wasn't robust because (a) some thread ids can 
be negative numbers and (b) sometimes you'd get a 'cannot access memory' error 
in printing out a prototype, and that would mess up the \n placement.

This patch fixes those two problems, and renames the tests to be unique.

tested on i686-pc-linux-gnu, ok?

nathan
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Nathan Sidwell    ::   http://www.codesourcery.com   ::         CodeSourcery
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