IPA sem equality pass introduction.
Test files for IPA sem equality added.
Merge remote-tracking branch 'parent/master'
IPA sem equality: type aliases added, bug fixed.
IPA sem equality: simplified SSA name handling.

IPA sem equality uses simple vector for SSA name tracking instead of
hash table.
New tests were added.
IPA sem equality: switch simple handling added.
Merge remote-tracking branch 'parent/master'
Small updates.
Storage reference handled in a simple manner.
Merge remote-tracking branch 'parent/master'
Vector fix in ipa-sem-equality.
Build scripts introduced.
IPA sem equality: References to storage enhanced.
IPA sem equality: const handled, local variables comaprison draft added.
IPA sem equality: VAR_DECL handled in a proper way.
IPA sem equality.c: pass clean up.
Merge remote-tracking branch 'parent/master'
IPA sem equality: enhanced gimple assignment operand handling.
IPA sem equality: switch labels are checked by value.
Tests for IPA sem equality checked a bit.