Convert JIT/opt to a merged test group (#85850)

Convert JIT/opt to a merged test group (#85850)

See https://github.com/markples/utils/tree/for-PR-dotnet-runtime-85847-others for ILTransform tool. In this group, I was a bit more aggressive in converting individual tests in [Fact]s and [Theory]s when needing to make manual changes. This required a change to the wrapper generator.

* Manual removal of C# Main args
* Mark async Main test as RPI
* Manual removal of IL Main arg
* Manual fix for badcallee
* [ILTransform -p] Remove _il from project name
* [ILTransform -n] Unique project names
* [ILTransform -m] Remove .module from IL tests
* Rename GitHub_42719: _r means not DebugType=Full, _o for optimize
* [ILTransform -a] Match IL .assembly names to project names
* [ILTransform -prociso] Set RequiresProcessIsolation when needed by other properties
* [ILTransform -sr] Use canonical form for .assembly extern System.Runtime
* [ILTransform -ilfact] Main->TestEntryPoint, [Fact], remove OutputType=Exe
* [ILTransform -public] Make test entrypoints accessible
* Manual fixes for [ILTransform -public] - internal methods to handle internal parameter types
* Handle float constants for InlineData in XUnitWrapperGenerator
* Manual fixes for xUnit1013 - internal methods, convert to [Theory]
* Manual fixes for xUnit1013 - internal methods, disable region
* Add merged group
* Fix mismatch{32,64} by putting the test methods in classes