Enregister EH var that are single def (#47307)

Enregister EH var that are single def (#47307)

* Enable EhWriteThry for SingleDef

* If EhWriteThru is enabled, DoNotEnregister if variable is not singleDef

* Revert code in ExecutionContext.RunInternal

* Revert code in AsyncMethodBuildCore.Start()

* Make sure we do not reset lvSingleDef

* Consitent display of frame offset

misc change in superpmi.py

* Use lvEHWriteThruCandidate

* Do not enregister EH Var that has single use

* do not enregister simdtype

* add missing comments

* jit format

* revert an unintended change

* jit format

* Add missing comments