Fix for PR28523: unexpected compilation error.

Clang emits error message for the following code:
```
template <class F> void parallel_loop(F &&f) { f(0); }

int main() {
  int x;
  parallel_loop([&](auto y) {
    {
      x = y;
    };
  });
}
```

$ clang++ --std=gnu++14 clang_test.cc -o clang_test
clang_test.cc:9:7: error: reference to local variable 'x' declared in enclosing function 'main'
      x = y;
            ^
clang_test.cc:2:48: note: in instantiation of function template specialization 'main()::(anonymous class)::operator()<int>' requested here
            template <class F> void parallel_loop(F &&f) { f(0); }
                                                           ^
clang_test.cc:6:3: note: in instantiation of function template specialization 'parallel_loop<(lambda at clang_test.cc:6:17)>' requested here parallel_loop([&](auto y) {
           ^
clang_test.cc:5:7: note: 'x' declared here
      int x;
          ^
1 error generated.

Patch fixes this issue.

llvm-svn: 286584

1 files changed, 2 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 114dba31d93..fae8bf0f548 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -14079,7 +14079,8 @@ static void DoMarkVarDeclReferenced(Sema &SemaRef, SourceLocation Loc,
         (SemaRef.CurContext != Var->getDeclContext() &&
          Var->getDeclContext()->isFunctionOrMethod() && Var->hasLocalStorage());
     if (RefersToEnclosingScope) {
-      if (LambdaScopeInfo *const LSI = SemaRef.getCurLambda()) {
+      if (LambdaScopeInfo *const LSI =
+              SemaRef.getCurLambda(/*IgnoreCapturedRegions=*/true)) {
         // If a variable could potentially be odr-used, defer marking it so
         // until we finish analyzing the full expression for any
         // lvalue-to-rvalue