Refactor DynamicLibrary so searching for a symbol will have a defined order and
libraries are properly unloaded when llvm_shutdown is called.
Summary:
This was mostly affecting usage of the JIT, where storing the library handles in
a set made iteration unordered/undefined. This lead to disagreement between the
JIT and native code as to what the address and implementation of particularly on
Windows with stdlib functions:
JIT: putenv_s("TEST", "VALUE") // called msvcrt.dll, putenv_s
JIT: getenv("TEST") -> "VALUE" // called msvcrt.dll, getenv
Native: getenv("TEST") -> NULL // called ucrt.dll, getenv
Also fixed is the issue of DynamicLibrary::getPermanentLibrary(0,0) on Windows
not giving priority to the process' symbols as it did on Unix.
Reviewers: chapuni, v.g.vassilev, lhames
Reviewed By: lhames
Subscribers: danalbert, srhines, mgorny, vsk, llvm-commits
Differential Revision: https://reviews.llvm.org/D30107
llvm-svn: 301236