Re-apply "[analyzer] Model trivial copy/move ctors with an aggregate bind."

...after a host of optimizations related to the use of LazyCompoundVals
(our implementation of aggregate binds).

Originally applied in r173951.
Reverted in r174069 because it was causing hangs.
Re-applied in r174212.
Reverted in r174265 because it was /still/ causing hangs.

If this needs to be reverted again it will be punted to far in the future.

llvm-svn: 175234