Eliminate the ItaniumVTableContext object from CodeGenVTables

Now CodeGenVTables has only one VTableContext object, which is either
Itanium or Microsoft.

Fixes a FIXME with no functionality change intended.

Ideally we could avoid the downcasts by pushing the things that
reference the Itanium vtable context into ItaniumCXXABI.cpp, but we're
not there yet.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@197845 91177308-0d34-0410-b5e6-96231b3b80d8
Don't mark record decls invalid when one of its methods is invalid, PR18284.

Without this patch, record decls with invalid out-of-line method delcs would
sometimes be marked invalid, but not always.  With this patch, they are
consistently never marked invalid.

(The code to do this was added in
http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20100809/033154.html
, but the test from that revision is still passing.)

As far as I can tell, this was the only place where a class was marked invalid
after its definition was complete.



git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@197848 91177308-0d34-0410-b5e6-96231b3b80d8