Fixed a FIXME; created a print method for Selectors that accepts a raw_ostream, and started using it in places it made sense.

No functional changes intended, just API cleanliness.

llvm-svn: 198428
diff --git a/clang/lib/StaticAnalyzer/Checkers/CallAndMessageChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CallAndMessageChecker.cpp
index fefcbe7..8918cd1 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CallAndMessageChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CallAndMessageChecker.cpp
@@ -426,8 +426,9 @@
 
   SmallString<200> buf;
   llvm::raw_svector_ostream os(buf);
-  os << "The receiver of message '" << ME->getSelector().getAsString()
-     << "' is nil";
+  os << "The receiver of message '";
+  ME->getSelector().print(os);
+  os << "' is nil";
   if (ResTy->isReferenceType()) {
     os << ", which results in forming a null reference";
   } else {