Use a proper lvalue-to-rvalue conversion in Objective-C++ property accessors.

Previously, the synthesized AST contained an rvalue DeclRefExpr for 'self'.
Now, it has an lvalue DeclRefExpr wrapped in an lvalue-to-rvalue
ImplicitCastExpr, which is what's generated when an ivar access is written
in the source.

No (intended) functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@199225 91177308-0d34-0410-b5e6-96231b3b80d8
[analyzer] Use synthesized ASTs for property getters when available.

This allows the analyzer to handle properties with C++ class type,
finishing up the FIXME from r198953.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@199226 91177308-0d34-0410-b5e6-96231b3b80d8
CFG: use Visit instead of VisitStmt to look through parens.

PR18472

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@199227 91177308-0d34-0410-b5e6-96231b3b80d8
Simplifying the OpenCL image attribute. It does not need a semantic integer parameter because the required information is encoded in the spelling. Added an appropriate subject to the attribute, and simplified the semantic checking (which will likely be expanded upon in a future patch). Also, removed the GNU spelling since it was unsupported in the first place.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@199229 91177308-0d34-0410-b5e6-96231b3b80d8