Moved the ModuleLoader and supporting helper loadModuleFromBuffer out of
ThinLTOCodeGenerator and into new LTO.h/LTO.cpp files. This is in
preparation for a patch that will utilize these in the gold-plugin.
Note that there are some other pending patches (D20268 and D20290) that
also plan to refactor common interfaces and functionality into this same
pair of new files.
llvm-svn: 270509