fix clang warning
change LC_OPT_ENT_BOOL to take a bool instead of an int destination
ia32_emitter: cleanup, use C99
node_cmp_attr changed to node_attrs_equal and code cleaned up
bestack: code cleanup, use C99
benode: cleanup, use C99
use designated initializers for arch_irn_ops
beschednormal: cleanup
remove regpress and trace schedulers

In their current state they produce very bad code and are just a
maintenance burden.
rework and cleanup schedulers

Make the list scheduler a set of helper functions, instead of a complex
design with a set of callbacks.
Simplified list scheduler code.
amd64: Exchange SSE Sub with Neg + Add