LLVM: Add support for TNTC to LLVM compiler suite
At the moment we handle TNTC in the LLVM backend in two different ways:
Linux/Windows: We use the GNU As subsections feature to order sections. Works very nicely. Slight hack in that we create special section names that contain comments. (Asm injection)
Mac: Mac assembler doesn't support the GNU As subsections feature, so we post-process the assembly code produced by llc.
Both these methods (especially Mac) are hacks. It would be better to extend LLVM to support the TNTC feature.