ModuleBuilder.GetType does not work with ignore case with certain unicode chars on Unix

[hughbe]

The following test passes on Windows, but fails on non-Windows platforms, discovered in dotnet/corefx#10532

[Fact]
public void Test()
{
    AssemblyBuilder assemblyBuilder = AssemblyBuilder.DefineDynamicAssembly(new AssemblyName("AssemblyName"), AssemblyBuilderAccess.Run);
    ModuleBuilder moduleBuilder = assemblyBuilder.DefineDynamicModule("ModuleName");

    TypeBuilder type = moduleBuilder.DefineType("\uD800\uDC00");
    TypeInfo createdType = type.CreateTypeInfo();

    moduleBuilder.GetType("\uD800\uDC00", false, false); // Works on all platforms
    moduleBuilder.GetType("\uD800\uDC00", true, false); // Works on all platforms

    moduleBuilder.GetType("\uD800\uDC00", true, true); // Throws TypeLoadException on Unix
    moduleBuilder.GetType("\uD800\uDC00".ToLowerInvariant(), true, true); // Throws TypeLoadException on Unix
    moduleBuilder.GetType("\uD800\uDC00".ToUpperInvariant(), true, true); // Throws TypeLoadException on Unix}

/cc @stephentoub @atsushikan

[stephentoub]

cc: @tarekgh, @ellismg

[tarekgh]

@atsushikan please have a look and if you see the issue is globalization I will help with it. Thanks.

[tarekgh]

moved it to 1.2 as this is rare scenario to support surrogate pairs in types names

[karelz]

Next step: Find out (under debugger) where we invoke globalization and get the wrong answer (that's where it is likely going to be).

[KristinXie1]

https://github.com/dotnet/corefx/blob/master/src/System.Reflection.Emit/tests/Utilities.cs#L102