swift234

[sil-aa] Change TBAA to use type oracle instructions instead of the raw types of instructions.

The reason that this is important is that we *ARE* allowing the stdlib
to perform certain types of type punning for efficiency implying we need
to have a type oracle instruction to have safety.

A type oracle instruction is an instruction which implies undefined behavior
unless its operand/result is of a certain type (allowing us to ignore that
possibility).

In a following commit I am going to go over and fix any problems in the
actual TBAA implementation and give all the various checks tests.

rdar://16651852

Swift SVN r18090