Clean CodeGen::genEmitCall (dotnet/coreclr#19804)

Clean CodeGen::genEmitCall (dotnet/coreclr#19804)

* delete isProfLeaveCB from arm signature

The previous implementation was done many years ago and I do not why it was done that way.

* extract GetSavedSet

* add isNoGCHelper

* delete isNoGC arg

* move declarations closer to their uses

* delete isGc from genEmitCall

* delete unused method declaration.

* add emitNoGChelper that accepts CORINFO_METHOD_HANDLE

* fix missed switch cases

* add function headers

* Fix feedback

* Fix feedback2

Commit migrated from https://github.com/dotnet/coreclr/commit/e80e55a1ace4b4de10072b0f6f71f79aca868906