Add a C API to the LLVM LTO library

[chandlerc]

Bugzilla Link	1081
Resolution	FIXED
Resolved on	Feb 22, 2010 12:55
Version	trunk
OS	Linux
Attachments	[includehttps://user-images.githubusercontent.com/711534/143736758-7c498307-76f4-4ec3-89e2-82a62d8c9229.gz), [toolshttps://user-images.githubusercontent.com/711534/143736759-a2a7e217-0486-443e-8f0c-26ced9f5a208.gz)

Extended Description

In trying to integrate LLVM into GNU ld, it became necessary to have a C API for
the LTO. Rather than place C++, LLVM-specific code into the GNU linker, it
seemed more appropriate to include a C interface within LLVM itself. The files
and patches here will hopefully accomplish this in a smooth and unobtrusive manner.

[lattner]

Applied! I made a couple of minor changes (brace placement, wrap to 80 lines etc), but nothing
functional.

Nice work,

-Chris