Add EmitDifferenceOptions

## Background and Motivation

Hot Reload: The IDE needs to configure the compiler to emit different code based on the capabilities of the runtime.

## Proposed API

```diff
namespace Microsoft.CodeAnalysis.Emit;

class Compilation
{
public EmitDifferenceResult EmitDifference(
EmitBaseline baseline,
IEnumerable edits,
Func isAddedSymbol,
Stream metadataStream,
Stream ilStream,
Stream pdbStream,
+ EmitDifferenceOptions options,
CancellationToken cancellationToken);
}

+public readonly struct EmitDifferenceOptions
+{
+ public static readonly EmitDifferenceOptions Default;
+
+ ///
+ /// True to emit FieldRva table entries. The runtime must support this feature.
+ ///
+ public bool EmitFieldRva { get; init; }
+
+ public EmitDifferenceOptions();
}
```

## Usage Examples

## Alternative Designs

## Risks