Created attachment 579556 [details] [diff] [review] Ensure that JM compilation doesn't used out-of-date ScriptAnalysis structures. The contents of a ScriptAnalysis depend on the value of debugMode; for example, see the way usesReturnValue_ gets set in ScriptAnalysis::analyzeByteCode. In some cases, the compiler may try to use a ScriptAnalysis created before debug mode was turned on to generate code when debug mode is on, leading to... Undesirable Consequences [orchestra spike]. Some tests in js/src/jit-test/tests/debug cause the assertions in the attached patch to fail, if you comment out the call to JSScript::clearAnalysis that it adds.
Try server run: https://tbpl.mozilla.org/?tree=Try&rev=48fe5b5d6aa3