[aot] Add JustInterp Mode to the MonoAOTCompiler task (#52560)

In this mode we pass `--aot=interp` to the AOT compiler.  This will _not_ AOT
the managed methods in the specified assemblies, but it will AOT the
trampolines and wrappers necessary for the interpreter to run the methods and
to interoperate with native P/Invokes and unmanaged callbacks.

src/tasks/AotCompilerTask/MonoAOTCompiler.cs

@@ -99,9 +99,10 @@ public class MonoAOTCompiler : Microsoft.Build.Utilities.Task
     public string? AotModulesTableLanguage { get; set; } = nameof(MonoAotModulesTableLanguage.C);
 
     /// <summary>
-    /// Choose between 'Normal', 'Full', 'FullInterp', 'LLVMOnly', 'LLVMOnlyInterp'.
+    /// Choose between 'Normal', 'JustInterp', 'Full', 'FullInterp', 'LLVMOnly', 'LLVMOnlyInterp'.
     /// LLVMOnly means to use only LLVM for FullAOT, AOT result will be a LLVM Bitcode file (the cross-compiler must be built with LLVM support)
     /// The "interp" options ('LLVMOnlyInterp' and 'FullInterp') mean generate necessary support to fall back to interpreter if AOT code is not possible for some methods.
+    /// The difference between 'JustInterp' and 'FullInterp' is that 'FullInterp' will AOT all the methods in the given assemblies, while 'JustInterp' will only AOT the wrappers and trampolines necessary for the runtime to execute the managed methods using the interpreter and to interoperate with P/Invokes and unmanaged callbacks.
     /// </summary>
     public string Mode { get; set; } = nameof(MonoAotMode.Normal);
 
@@ -327,7 +328,7 @@ private bool PrecompileLibrary(ITaskItem assemblyItem, string? monoPaths)
                 aotArgs.Add("full");
             }
 
-            if (parsedAotMode == MonoAotMode.FullInterp)
+            if (parsedAotMode == MonoAotMode.FullInterp || parsedAotMode == MonoAotMode.JustInterp)
             {
                 aotArgs.Add("interp");
             }
@@ -509,6 +510,7 @@ private void GenerateAotModulesTable(ITaskItem[] assemblies, string[]? profilers
 public enum MonoAotMode
 {
     Normal,
+    JustInterp,
     Full,
     FullInterp,
     LLVMOnly,