objective-C arc: in copy helper function for 
__strong __block variables, perform objc_storeStrong on
source and destination instead of direct move. This 
is done with -O0 and to improve some analysis.
// rdar://12530881


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171555 91177308-0d34-0410-b5e6-96231b3b80d8
Various fixes to clang-format's macro handling.

Some of this is still pretty rough (note the load of FIXMEs), but it is
strictly an improvement and fixes various bugs that were related to
macro processing but are also imporant in non-macro use cases.

Specific fixes:
- correctly puts espaced newlines at the end of the line
- fixes counting of white space before a token when escaped newlines are
  present
- fixes parsing of "trailing" tokens when eof() is hit
- puts macro parsing orthogonal to parsing other structure
- general support for parsing of macro definitions

Due to the fix to format trailing tokens, this change also includes a
bunch of fixes to the c-index tests.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171556 91177308-0d34-0410-b5e6-96231b3b80d8
Update checker build to checker-270

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171560 91177308-0d34-0410-b5e6-96231b3b80d8