move #define to the beginning of the header

This makes it consistent with the rest of libFirm and avoids cases where
the non-inlined version of the functions is used inside the header by accident.
fix arm backend
get rid of an explicit Rotl node

The backends which support rotl now match for or(shl,shr) patterns.
remove incorrect documentation
cleanup, use C99
add tarval_to_uint64(), tarval_is_uint64()
amd64: rework and fix Const/SymConst nodes
amd64: fix broken Perm emitter
amd64: fix not/neg mode
amd64: fix Proj(Cond) transform
amd64: use 32/64bit versions of binops
amd64: implement Div+Mod
amd64: remove some pointless and sometimes wrong comments
Added fallback solutions for execution frequency.

If the solution of our eigenvalue problem results in unreasonable values
(like infinity), we now fall back to a loop-weight-based execution
frequency, or, if this is not sufficient, to a constant execution
frequency.