[wasm][coreclr] GetUnmanagedCallersOnlyThunk: unknown thunk for unmanaged callers only method

Some runtime tests have methods decorated with `UnmanagedCallersOnly` attribute. These will require native relinking.

They fail like this:
```
11:48:33.449 Running test: JIT/opt/Regressions/Regression3_Regressions/Regression3_Regressions.dll
ASSERT FAILED
Expression: false && "GetUnmanagedCallersOnlyThunk: unknown thunk for unmanaged callers only method"
Location: /__w/1/s/src/coreclr/vm/wasm/helpers.cpp:746
Function: GetUnmanagedCallersOnlyThunk
Process: 42
Frame (InlinedCallFrame): 0x4fdc54
Skipping 0x4fdc54
Frame (InterpreterFrame): 0x4fede8
0) dynamicClass::IL_STUB_PInvoke, IR_004a
1) System.Reflection.RuntimeAssembly::GetTypeCore, IR_015c
2) System.Reflection.RuntimeAssembly::GetTypeCore, IR_006d
3) System.Reflection.TypeNameResolver::GetType, IR_0278
4) System.Reflection.TypeNameResolver::GetSimpleType, IR_00bb
5) System.Reflection.TypeNameResolver::Resolve, IR_0018
6) System.Reflection.TypeNameResolver::GetType, IR_0099
7) System.Reflection.RuntimeAssembly::GetType, IR_002a
8) System.Reflection.Assembly::GetType, IR_001b
9) Program::TestEntryPoint, IR_002e
10) Program::<$>g__TestExecutor134|0_135, IR_005b
11) Program::$, IR_07b9
```