[clang][Interp] Fix record initialization from temporary in initlist

Author: tbaederr

clang/lib/AST/Interp/ByteCodeExprGen.cpp

@@ -863,6 +863,10 @@ bool ByteCodeExprGen<Emitter>::visitInitList(ArrayRef<const Expr *> Inits,
   assert(E->getType()->isRecordType());
   const Record *R = getRecord(E->getType());
 
+  if (Inits.size() == 1 && E->getType() == Inits[0]->getType()) {
+    return this->visitInitializer(Inits[0]);
+  }
+
   unsigned InitIndex = 0;
   for (const Expr *Init : Inits) {
     if (!this->emitDupPtr(E))

clang/test/AST/Interp/records.cpp

@@ -7,6 +7,10 @@
 // RUN: %clang_cc1 -verify=ref -std=c++20 %s
 // RUN: %clang_cc1 -verify=ref -triple i686 %s
 
+/// Used to crash.
+struct Empty {};
+constexpr Empty e = {Empty()};
+
 struct BoolPair {
   bool first;
   bool second;

clang/test/SemaCXX/cxx1z-copy-omission.cpp

@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -std=c++1z -verify -Wno-unused %s
+// RUN: %clang_cc1 -std=c++1z -verify -Wno-unused %s -fexperimental-new-constant-interpreter
 
 struct Noncopyable {
   Noncopyable();