--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/PCH/cxx2a-bitfield-init.cpp	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -std=c++2a -include %s -verify %s
+// RUN: %clang_cc1 -std=c++2a -emit-pch %s -o %t
+// RUN: %clang_cc1 -std=c++2a -include-pch %t -verify %s -DPCH
+
+#ifndef HEADER
+#define HEADER
+
+struct S {
+  unsigned int n : 5 = 49; // expected-warning {{changes value}}
+};
+
+int a;
+template<bool B> struct T {
+  int m : B ? 8 : a = 42;
+};
+
+#else
+
+// expected-error@-5 {{constant expression}} expected-note@-5 {{cannot modify}}
+
+static_assert(S().n == 17);
+static_assert(T<true>().m == 0);
+int q = T<false>().m; // expected-note {{instantiation of}}
+
+#endif