Abstract the behavior of when to use base-class tail padding.

For fun, I added a comedy "actually obey the C++11 POD rules" option
which nobody is allowed to use.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173744 91177308-0d34-0410-b5e6-96231b3b80d8
Replace AS_MSTypespec with AS_Keyword, for representing any attribute spelled
as a keyword. Rationalize existing attributes to use it as appropriate, and to
not lie about some __declspec attributes being GNU attributes. In passing,
remove a gross hack which was discarding attributes which we could handle. This
results in us actually respecting the __pascal keyword again.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173746 91177308-0d34-0410-b5e6-96231b3b80d8
Don't crash while printing APValues that are lvalues casted to a
decidedly non-reference, non-pointer type. Fixes <rdar://problem/13090123>.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173747 91177308-0d34-0410-b5e6-96231b3b80d8
Actually remove the hack which was blocking the Borland-style attributes from
working, and add the missing attribute spellings. This brings _pascal,
_fastcall, _stdcall and _cdecl to life in -fborland-extensions mode.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173749 91177308-0d34-0410-b5e6-96231b3b80d8
Treat alignas and _Alignas as keyword attributes. This allows us to
pretty-print them properly (modulo the more general badness in alignment
attribute printing).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173752 91177308-0d34-0410-b5e6-96231b3b80d8