Simple IPA sem equality: stats fixed.
Merge remote-tracking branch 'parent/master' into simple-ipa-sem-equality
Semi-working commit.
IPA sem equality: congruence reduction works, clean up is needed.
IPA sem equality: congruence group merging finalized.
Merge remote-tracking branch 'parent/master' into simple-ipa-sem-equality
IPA sem equality: congruence tests added.
IPA sem equality: memory usage reduced and speeded up.

Large memory consumption reduced by introduction of
bitmap obstack. func_func_by_decl is accelerated by hashtable.
IPA sem equality: algorithm speeded up.
IPA sem equality: pass cleaned up, memory release in an appropriate way.
IPA sem equality: pass compilation fixed.
IPA sem equality: stats fixed.
IPA sem equality: another stats fix.
IPA sem equality: small clean up done.
Correct function alias merging is done.
Merge remote-tracking branch 'parent/master' into simple-ipa-sem-equality
IPA sem equality: merging changed a bit.
IPA sem equality: PHI node comparison fixed.

More sensitive function merging approach introduced.
IPA sem equality: SELF CHECK mode desinged.

Tester fixed.
IPA sem equality: pass cleaned up.