[CFG] [analyzer] Add stubs for constructor and message argument constructors.

[CFG] [analyzer] Add stubs for constructor and message argument constructors.

CFG now correctly identifies construction context for temporaries constructed
for the purpose of passing into a function as an argument.

Such context is still not fully implemented because the information it provides
is not rich enough: it doens't contain information about argument index.
It will be addresssed later.

This patch is an extension of r330377 to C++ construct-expressions and
Objective-C message expressions which aren't call-expressions but require
similar handling. C++ new-expressions with placement arguments still remain to
be handled.

Differential Revision: https://reviews.llvm.org/D49826

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@338425 91177308-0d34-0410-b5e6-96231b3b80d8