[analyzer] Construct temporary objects of correct types, destroy them properly.

When constructing a temporary object region, which represents the result of
MaterializeTemporaryExpr, track down the sub-expression for which the temporary
is necessary with a trick similar to the approach used in CodeGen, namely
by using Expr::skipRValueSubobjectAdjustments().

Then, create the temporary object region with type of that sub-expression.
That type would propagate further in a path-sensitive manner.

During destruction of lifetime-extened temporaries, consult the type of
the temporary object region, rather than the type of the lifetime-extending
variable, in order to call the correct destructor (fixes pr17001) and,
at least, not to crash by trying to call a destructor of a plain type
(fixes pr19539).

rdar://problem/29131302
rdar://problem/29131576

Differential Revision: https://reviews.llvm.org/D26839

llvm-svn: 288263