Current generation of entrypoint glue code works only for packages with entry functions defined in a single module. These changes move entrypoint glue code generation outside ModuleContext. The glue code is generated in a separate LLVM module, so that it can make calls to entry functions defined in any module of a package.
Test Plan
Added rbpf-tests test with entry functions in different modules.
Motivation
Current generation of entrypoint glue code works only for packages with entry functions defined in a single module. These changes move entrypoint glue code generation outside ModuleContext. The glue code is generated in a separate LLVM module, so that it can make calls to entry functions defined in any module of a package.
Test Plan
Added rbpf-tests test with entry functions in different modules.
Resolves #369