Remove getVTT* in favor of getStructorImplicitParameter*

No functionality change.  The only remaining uses were in ItaniumCXXABI,
which knows the implicit parameter is a VTT.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197189 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "[-cxx-abi microsoft] Mangle reference temporaries"

This reverts commit r197184.

Richard Smith brings up some good points, a proper implementation will
require us to mangle unnameable entities compatibly with MSVC.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197192 91177308-0d34-0410-b5e6-96231b3b80d8
[-cxx-abi microsoft] Add commentary for mangleStaticGuardVariable

We will need to do some work here if we want to play nice with MSVC2013.
Add a TODO indicating what changed and why this matters.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197193 91177308-0d34-0410-b5e6-96231b3b80d8
Move C++ destructor emission into CGCXXABI

No functionality change.  Only Itanium C++ destructors have implicit VTT
parameters.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197194 91177308-0d34-0410-b5e6-96231b3b80d8
AST: Update URL for Itanium ABI spec

The old URL hasn't worked for quite some time.  While we are here, also
change the link so that it will send us straight to the mangling portion
of the ABI doc.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197195 91177308-0d34-0410-b5e6-96231b3b80d8