Move away from exposing internal EventPipe wait handle to EventPipeEventDispatcher.

[lateralusX]

Fix for issue, #68032.

EventPipe exposed and internal wait handle to EventPipeEventDispatcher. The wait handle is not a managed WaitableObject, but maps to runtime specific event types:

CLREventStatic * on CoreCLR
mono_w32event_create on Mono

Overtime it appears that the underlying WaitHandle changed on none Windows platforms, so calls like:

EventWaitHandle.Set

Assumes that IntPtr used is a WaitableObject and on Mono this will cause a crash, but on CoreCLR, it will just be casted over to a WaitableObject and use it, so based on memory layout this could cause issue, but looking at the implementation, it appears it will always assume EventWaitHandle is signaled so won't touch any of the memory (but not signal the event).

There have been an ambition in DispatchEventsToEventListeners to move this abstraction down into native code, get away from using a handle returned from EventPipeInternal.GetWaitHandle as a EventWaitHandle. This PR eliminate EventPipeInternal.GetWaitHandle and adds a SignalSession and WaitForSessionSignal icall's (Mono), qcall's (CoreCLR) and fix the issue caused by exposing the handle to managed code.

[lateralusX]

CC @josalem

[josalem]

LGTM 👍 . There are going to be code conflicts once the other PR merges, but they should be easy to clean up. Just fighting some new CodeAnalysis rules and that should be ready for merging.

[lateralusX]

@josalem Rebased after merge of #67150 and re-enable disabled test on Mono.

[lateralusX]

Test needs to be disabled on browser since EventPipe is not running on that platform.
Not sure about failure in llvmaot, but could be due to disabled EventPipe as well, will check.

[josalem]

/azp run runtime

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[lateralusX]

Failures looks infra related, test suite pass but seems to be permission related errors on phyton script:

Traceback (most recent call last):
  File "/root/helix/work/correlation/reporter/run.py", line 13, in <module>
    from test_results_reader import read_results
  File "/root/helix/work/correlation/reporter/test_results_reader/__init__.py", line 3, in <module>
    from helix.public import TestResult, TestResultAttachment
  File "/root/helix/scripts/helix/public/__init__.py", line 5, in <module>
    import helix.event
  File "/root/helix/scripts/helix/event.py", line 7, in <module>
    import helix.logs
  File "/root/helix/scripts/helix/logs.py", line 43, in <module>
    rotating_file_handler = RotatingFileHandler(log_file_path, maxBytes=20000000, backupCount=10)
  File "/usr/lib/python3.7/logging/handlers.py", line 147, in __init__
    BaseRotatingHandler.__init__(self, filename, mode, encoding, delay)
  File "/usr/lib/python3.7/logging/handlers.py", line 54, in __init__
    logging.FileHandler.__init__(self, filename, mode, encoding, delay)
  File "/usr/lib/python3.7/logging/__init__.py", line 1092, in __init__
    StreamHandler.__init__(self, self._open())
  File "/usr/lib/python3.7/logging/__init__.py", line 1121, in _open
    return open(self.baseFilename, self.mode, encoding=self.encoding)
PermissionError: [Errno 13] Permission denied: '/root/helix/logs/run.py.log'

Same error occurs on other PR's.

[lateralusX]

Will investigate CoreCLR failing tests.

[lateralusX]

All pass, so could be an intermediate failure, will re-run runtime tests on more time.

[lateralusX]

/azp run runtime

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[lateralusX]

All pass again, looks good.