[Sema] Recontextualize BreakStmt + ContinueStmt in lazy vars

I don't think this currently matters, but ensure
we re-contextualize BreakStmts and ContinueStmts
in RecontextualizeClosures since these statements
store DeclContexts.

Author: hamishknight

include/swift/AST/Stmt.h

@@ -1613,6 +1613,7 @@ class BreakStmt : public Stmt {
   }
 
   DeclContext *getDeclContext() const { return DC; }
+  void setDeclContext(DeclContext *newDC) { DC = newDC; }
 
   static bool classof(const Stmt *S) {
     return S->getKind() == StmtKind::Break;
@@ -1648,6 +1649,7 @@ class ContinueStmt : public Stmt {
   }
 
   DeclContext *getDeclContext() const { return DC; }
+  void setDeclContext(DeclContext *newDC) { DC = newDC; }
 
   static bool classof(const Stmt *S) {
     return S->getKind() == StmtKind::Continue;

lib/Sema/TypeCheckStorage.cpp

@@ -1588,6 +1588,12 @@ namespace {
         for (auto *CaseVar : CS->getCaseBodyVariablesOrEmptyArray())
           CaseVar->setDeclContext(NewDC);
       }
+      // A few statements store DeclContexts, update them.
+      if (auto *BS = dyn_cast<BreakStmt>(S))
+        BS->setDeclContext(NewDC);
+      if (auto *CS = dyn_cast<ContinueStmt>(S))
+        CS->setDeclContext(NewDC);
+
       return Action::Continue(S);
     }