Allow the external AST source to provide a layout without specifying the alignment (because it's not encoded in DWARF). In this case, make an educated guess at the alignment.
Allow the external AST source to provide a layout without specifying
the alignment (because it's not encoded in DWARF). In this case, make
an educated guess at the alignment.


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@149161 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang