Log Message:
Update to libfirm-1.15.0:
* Implementation of Clicks Combined Analysis/Optimisations
* New switch lowering code
* support for global asm statements
* improved asm support
* PIC support for Mac OS X
* New register pressure minimizing scheduler
* Improvements to spill algorithm
* fix endless loop problems
* further improve inlining heuristics
* improve peephole optimisations for x86
* bugfixes