Allow externally dlopen-ed libraries to be registered as permanent libraries.

This is also useful in cases when llvm is in a shared library. First we dlopen
the llvm shared library and then we register it as a permanent library in order
to keep the JIT and other services working.

Patch reviewed by Vedant Kumar (D29955)!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296442 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed