Fix a crash-on-invalid where the constant evaluator would try to
evaluate certain expressions involving invalidly-defined classes.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@155645 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 8185481..2edf4ff 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -3408,6 +3408,7 @@
 
 bool RecordExprEvaluator::ZeroInitialization(const Expr *E) {
   const RecordDecl *RD = E->getType()->castAs<RecordType>()->getDecl();
+  if (RD->isInvalidDecl()) return false;
   if (RD->isUnion()) {
     // C++11 [dcl.init]p5: If T is a (possibly cv-qualified) union type, the
     // object's first non-static named data member is zero-initialized
@@ -3470,6 +3471,8 @@
     return false;
 
   const RecordDecl *RD = E->getType()->castAs<RecordType>()->getDecl();
+  if (RD->isInvalidDecl()) return false;
+
   const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(RD);
 
   if (RD->isUnion()) {
@@ -3528,6 +3531,8 @@
 
 bool RecordExprEvaluator::VisitCXXConstructExpr(const CXXConstructExpr *E) {
   const CXXConstructorDecl *FD = E->getConstructor();
+  if (FD->isInvalidDecl() || FD->getParent()->isInvalidDecl()) return false;
+
   bool ZeroInit = E->requiresZeroInitialization();
   if (CheckTrivialDefaultConstructor(Info, E->getExprLoc(), FD, ZeroInit)) {
     // If we've already performed zero-initialization, we're already done.