[clang] Add zero-initialization for fixed point types

Author: PiJoules

clang/lib/AST/ExprConstant.cpp

@@ -11427,6 +11427,10 @@ class FixedPointExprEvaluator
     return true;
   }
 
+  bool ZeroInitialization(const Expr *E) {
+    return Success(0, E);
+  }
+
   //===--------------------------------------------------------------------===//
   //                            Visitor Methods
   //===--------------------------------------------------------------------===//

clang/test/CodeGenCXX/fixed-point-zero-init.cpp

@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -ffixed-point -S -emit-llvm %s -o - | FileCheck %s
+
+// CHECK: @_ZL1a = internal constant [2 x i32] zeroinitializer
+constexpr _Accum a[2] = {};
+
+void func2(const _Accum *);
+void func() {
+  func2(a);
+}