remove a bunch of unused private methods
found with a smarter version of -Wunused-member-function that I'm playwing with.
Appologies in advance if I removed someone's WIP code.

 ARCMigrate/TransProperties.cpp                  |    8 -----
 AST/MicrosoftMangle.cpp                         |    1
 Analysis/AnalysisDeclContext.cpp                |    5 ---
 Analysis/LiveVariables.cpp                      |   14 ----------
 Index/USRGeneration.cpp                         |   10 -------
 Sema/Sema.cpp                                   |   33 +++++++++++++++++++++---
 Sema/SemaChecking.cpp                           |    3 --
 Sema/SemaDecl.cpp                               |   20 ++------------
 StaticAnalyzer/Checkers/GenericTaintChecker.cpp |    1
 9 files changed, 34 insertions(+), 61 deletions(-)