Tracelogger is continuously disabling itself early due to bad script event id's that are being started. This problem is specific to generator JSOP RESUME opcodes, the script events that are passed in with emitTraceLoggerResume() are always garbage.
This appears to be because the baseline script is no longer loaded in the scratch1 register here: https://searchfox.org/mozilla-central/rev/b949ce10fd1d90e70a14b31dfdb72a3911d57108/js/src/jit/BaselineCompiler.cpp#5647-5656
Tracelogger is no longer functioning properly because of bad script event ids. The baselinescript load into scratch1 was accidentally removed leading garbage script ids to be passed into emitTraceLoggerResume. This fix aims to simply reload the correct value back into scratch1 before calling tracelogger.
Pushed by email@example.com:
Load the baselinescript into scratch1 before calling emitTraceLoggerResume r=jandem