reassoc: remove a - C => a + (-C) rule, localopt already does that
reassoc: cleanup, use C99
amd64: fix warnings and slightly improve vcg dumping
amd64: fix warning
amd64: fix wrong parameter order

Didn't notice this before because gcc doesn't report a warning for this,
clang does.
Added localopt according to issue 0000136.

Mux((a & (1 << c)) != (b & (1 << c)), 0, 1) => (a ^ b) >> c.
Improved single bit recognition.
Use constbits API for occult constants.
Fixed indentation.
Simplified constbits API.

- Managed resources within the analysis itself
- Let constbits take care of the obstack to store the bit information
Revert "Improved single bit recognition."

This reverts commit 26e639c482a5c376bc89a9431bd2c37ba359b658.
We cannot benefit from bitinfo if we want *exactly* one bit.
Use get_tarval_popcount to recognize a power of two.
Fixed some typos.
Clear unused bits, i.e., normalize towards zero.
Fixed indentation.
Use tarval_andnot.
Improved DCA by using bit information.
be: Do not check for !mode when dumping backend node attributes.
amd64: Turn if-cascade into switch.
ir: Remove the unused function is_frame_pointer().