[PCH/Modules] The iterator may become invalidated because a new macro can be added while deserializing a macro, make sure to copy/move what we need from it.
[PCH/Modules] The iterator may become invalidated because a new macro can be added
while deserializing a macro, make sure to copy/move what we need from it.

Fixes clang-x86_64-debian-fast bot.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@172629 91177308-0d34-0410-b5e6-96231b3b80d8

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