Fix scrolling bug in clang-format's emacs integration.

This patch ensure that nothing scrolls even if the same buffer is opened
in multiple windows.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180252 91177308-0d34-0410-b5e6-96231b3b80d8
Add option to align escaped newlines left.

This enables formattings like:

  #define A   \
    int aaaa; \
    int b;    \
    int ccc;  \
    int dddddddddd;

Enabling this for Google/Chromium styles only as I don't know whether it
is desired for Clang/LLVM.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180253 91177308-0d34-0410-b5e6-96231b3b80d8
Don't mark 'extern "C" void f(void)' as having extern storage class.

Instead, we check for one line extern "C" context in linkage computation and
when deciding if a variable is a definition.

This hopefully completes the transition to having "as written" semantics for
hasExternalStorage.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180258 91177308-0d34-0410-b5e6-96231b3b80d8