[doc parsing]: don't attempt to fix single character
commands (\t \n are common). \\ rdar://12381408 


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181517 91177308-0d34-0410-b5e6-96231b3b80d8
Updating LibASTMatchersReference to include namespaceDecl()

The namespaceDecl() ASTMatcher was added in r179027.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181519 91177308-0d34-0410-b5e6-96231b3b80d8
[doc parsing]: So, in this patch, single character
'commands' will not go through typo fixit logic,
preserving the old behavior (no typo, no diagnostics).
// rdar://12381408


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181521 91177308-0d34-0410-b5e6-96231b3b80d8