r232842 added an assert that fires with the included testcase. Add an exception for '__thread_ptr' to canGoAfterDWARF().
Note: I don't know much about MC or whether this is the right thing to do. At a first glance this code looks like we should rather have a blacklist of sections that must not go after the dwarf sections rather than having a whitelist of sections that are allowed to go. (For example if you read ARMAsmPrinter::EmitEndOfAsmFile() there is another section called "Drectve" that is output after the debug info...