[analyzer] Handle inlined constructors for rvalue temporaries correctly.

Previously the analyzer treated all inlined constructors like lvalues,
setting the value of the CXXConstructExpr to the newly-constructed
region. However, some CXXConstructExprs behave like rvalues -- in
particular, the implicit copy constructor into a pass-by-value argument.
In this case, we want only the /contents/ of a temporary object to be
passed, so that we can use the same "copy each argument into the
parameter region" algorithm that we use for scalar arguments.

This may change when we start modeling destructors of temporaries,
but for now this is the last part of <rdar://problem/12137950>.

llvm-svn: 164830