Use ModuleReaderParameters::WorkingDirectory for assembly resolution

[Washi1337]

Problem Description

The implementation of AssemblyResolverBase uses its IList<string> SearchDirectories property to probe for assemblies matching the name provided by an AssemblyDescriptor. This search directories property is populated automatically with string ModuleDefinition::FilePath if it is not null or empty.

The FilePath property is only set when using ModuleDefinition.FromFile, but not when using any of the other FromXXX methods. This means the default assembly resolver does not know anything about the file location of the input binary, and thus also not any of its dependencies.

Proposal

Populate AssemblyResolverBase::SearchDirectories with ModuleReaderParameters::WorkingDirectory when not-null and/or are read from a source different than a file on the disk.

Alternatives

The user can manually add the working directory to the current AssemblyResolverBase instance. This, however, is a bit hidden behind ModuleDefinition::MetadataResolver::AssemblyResolver, and requires up-casting since AssemblyResolverBase is not the type that is directly exposed, making this process unintuitive.

Additional Context

string WorkingDirectory property is currently only used by the DefaultNetModuleResolver to resolve sub-modules of multi-module assemblies.