Bitcode link tool for le32-none-ndk triple.

Cherry-picked from release_32 branch with modifications.
Patch by Lai Wei-Chih <Robert.Lai@mediatek.com>
Patch by WenHan Gu <Wenhan.gu@mediatek.com>

Changes compared with the original patch:

1. llvm::Linker API changes:
   - Arguments of llvm::Linker() are changed
   - Rename LinkInModule() to linkInModule()
   - releaseModule() has been removed.  Use getModule() instead.
   - Several headers are moved to llvm/IR/*

2. Define the ControlFlags in LinkerConfig.

3. Link with "archive" component.