Don't walk a linked list twice in the same function. On my machine this takes "clang -cc1" on a file with 10k repetitions of extern int no_such_variable; from 1.434s to 1.133s.
Don't walk a linked list twice in the same function. On my machine this takes
"clang -cc1" on a file with 10k repetitions of
extern int no_such_variable;
from 1.434s to 1.133s.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@168394 91177308-0d34-0410-b5e6-96231b3b80d8

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