Make clang-format understand more line comments.

Apparently one needs to set LangOptions.LineComment.

Before "//* */" got reformatted to "/ /* */" as the lexer was returning
the token sequence (slash, comment). This could also lead to weird other
stuff, e.g. for people that like to using comments like:
//****************

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177720 91177308-0d34-0410-b5e6-96231b3b80d8
Fix DeclRefExpr::getFoundDecl() for usages by reference.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177721 91177308-0d34-0410-b5e6-96231b3b80d8
Documentation: fix a typo and formatting


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177722 91177308-0d34-0410-b5e6-96231b3b80d8
More precisely recognize ObjC method declarations.

Otherwise, +/- and the beginning of constants can be recognized
incorrectly.

Before:  #define A - 1
After:   #define A -1

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177725 91177308-0d34-0410-b5e6-96231b3b80d8