[Coverage] Support for C++17 switch initializers

Differential Revision: https://reviews.llvm.org/D25539

llvm-svn: 284292
diff --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
index 35d1b1d..403fbce 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.cpp
+++ b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -813,6 +813,8 @@
 
   void VisitSwitchStmt(const SwitchStmt *S) {
     extendRegion(S);
+    if (S->getInit())
+      Visit(S->getInit());
     Visit(S->getCond());
 
     BreakContinueStack.push_back(BreakContinue());