[CSA] [NFC] Move AnalysisContext.h to AnalysisDeclContext.h

The implementation is in AnalysisDeclContext.cpp and the class is called
AnalysisDeclContext.

Making those match up has numerous benefits, including:

 - Easier jump from header to/from implementation.
 - Easily identify filename from class.

Differential Revision: https://reviews.llvm.org/D37500

llvm-svn: 312671
diff --git a/clang/lib/Analysis/ThreadSafety.cpp b/clang/lib/Analysis/ThreadSafety.cpp
index 902570b..6a9c9a0 100644
--- a/clang/lib/Analysis/ThreadSafety.cpp
+++ b/clang/lib/Analysis/ThreadSafety.cpp
@@ -26,7 +26,7 @@
 #include "clang/Analysis/Analyses/ThreadSafetyLogical.h"
 #include "clang/Analysis/Analyses/ThreadSafetyTIL.h"
 #include "clang/Analysis/Analyses/ThreadSafetyTraverse.h"
-#include "clang/Analysis/AnalysisContext.h"
+#include "clang/Analysis/AnalysisDeclContext.h"
 #include "clang/Analysis/CFG.h"
 #include "clang/Analysis/CFGStmtMap.h"
 #include "clang/Basic/OperatorKinds.h"