The IR framework only prints the stdout if exitCode == 134:
https://github.com/openjdk/jdk/blob/cbe329b90ac1488836d4852fead79aa26c082114/test/hotspot/jtreg/compiler/lib/ir_framework/driver/TestVMProcess.java#L249

This works for VM crashes/asserts on Linux but not on Windows. As a result, the jtreg log is empty making it hard to identify/filter/link the failure.