[clang][bytecode] Handle DiscardResult for fixed-point literals (llvm#110475)

Author: tbaederr

clang/lib/AST/ByteCode/Compiler.cpp

@@ -763,6 +763,9 @@ bool Compiler<Emitter>::VisitFixedPointLiteral(const FixedPointLiteral *E) {
   assert(E->getType()->isFixedPointType());
   assert(classifyPrim(E) == PT_FixedPoint);
 
+  if (DiscardResult)
+    return true;
+
   auto Sem = Ctx.getASTContext().getFixedPointSemantics(E->getType());
   APInt Value = E->getValue();
   return this->emitConstFixedPoint(FixedPoint(Value, Sem), E);

clang/test/AST/ByteCode/fixed-point.cpp

@@ -11,6 +11,8 @@ static_assert(1.0k != 1.0k); // both-error {{failed due to requirement '1.0k !=
 static_assert(1.0k != 1); // both-error {{failed due to requirement '1.0k != 1'}}
 static_assert(-12.0k == -(-(-12.0k)));
 
+constexpr _Accum acc = (0.5r, 6.9k);
+
 /// Zero-init.
 constexpr _Accum A{};
 static_assert(A == 0.0k);

clang/test/Frontend/fixed_point_crash.c

@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -verify -ffixed-point %s
+// RUN: %clang_cc1 -verify -ffixed-point %s -fexperimental-new-constant-interpreter
 
 union a {
   _Accum x;