[NFC][analyzer] Fix static analyzer concerns

CFGStmtMap frees resources in the destructor but doesn't
have user-written copy c'tor or assignment operator, so copying it using
default ones can cause double free.

Reviewed By: cor3ntin

Differential Revision: https://reviews.llvm.org/D156415

clang/include/clang/Analysis/CFGStmtMap.h

@@ -26,6 +26,8 @@ class CFGStmtMap {
   void *M;
 
   CFGStmtMap(ParentMap *pm, void *m) : PM(pm), M(m) {}
+  CFGStmtMap(const CFGStmtMap &) = delete;
+  CFGStmtMap &operator=(const CFGStmtMap &) = delete;
 
 public:
   ~CFGStmtMap();