[Orc] Make the makeStub function propagate argument attributes onto the call to

[Orc] Make the makeStub function propagate argument attributes onto the call to
the function body.

This is necessary for correctness when lazily compiling.

Also, flesh out the Orc unit test infrastructure slightly, and add a unit test
for this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235347 91177308-0d34-0410-b5e6-96231b3b80d8