[clang][Interp] Fix ignored RequiresExprs

Also ConceptSpecializationExpr, although I don't have a test case
at hand for those.

Author: tbaederr

clang/lib/AST/Interp/ByteCodeExprGen.cpp

@@ -2440,13 +2440,17 @@ bool ByteCodeExprGen<Emitter>::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
 template <class Emitter>
 bool ByteCodeExprGen<Emitter>::VisitRequiresExpr(const RequiresExpr *E) {
   assert(classifyPrim(E->getType()) == PT_Bool);
+  if (DiscardResult)
+    return true;
   return this->emitConstBool(E->isSatisfied(), E);
 }
 
 template <class Emitter>
 bool ByteCodeExprGen<Emitter>::VisitConceptSpecializationExpr(
     const ConceptSpecializationExpr *E) {
   assert(classifyPrim(E->getType()) == PT_Bool);
+  if (DiscardResult)
+    return true;
   return this->emitConstBool(E->isSatisfied(), E);
 }
 

clang/test/AST/Interp/literals.cpp

@@ -985,6 +985,8 @@ namespace DiscardExprs {
     __uuidof(GuidType);
     __uuidof(number); // both-error {{cannot call operator __uuidof on a type with no GUID}}
 
+    requires{false;};
+
     return 0;
   }
   static_assert(ignoredExprs() == 0, "");