Synthesizing the definition of an implicit member is an AST modification, so notify any mutation listeners of it. This fixes a crasher in chained PCH, where an implicit destructor in a PCH gets a definition in a chained PCH, which is then lost. However, any further use of the destructor would cause its definition to be regenerated in the final file, hiding the bug.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@130103 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/PCH/chain-implicit-definition.cpp b/test/PCH/chain-implicit-definition.cpp
new file mode 100644
index 0000000..3ec4f62
--- /dev/null
+++ b/test/PCH/chain-implicit-definition.cpp
@@ -0,0 +1,39 @@
+// no PCH
+// RUN: %clang_cc1 -emit-llvm -o /dev/null -include %s -include %s %s
+// with PCH
+// RUN: %clang_cc1 -emit-llvm -o /dev/null -chain-include %s -chain-include %s %s
+#if !defined(PASS1)
+#define PASS1
+
+// A base with a virtual dtor.
+struct A {
+  virtual ~A();
+};
+
+// A derived class with an implicit virtual dtor.
+struct B : A {
+  // Key function to suppress vtable definition.
+  virtual void virt();
+};
+
+#elif !defined(PASS2)
+#define PASS2
+
+// Further derived class that requires ~B().
+// Causes definition of ~B(), but it was lost when saving PCH.
+struct C : B {
+  C();
+  ~C() {}
+};
+
+#else
+
+void foo() {
+  // Variable that requires ~C().
+  C c;
+}
+
+// VTable placement would again cause definition of ~B(), hiding the bug,
+// if not for B::virt(), which suppresses the placement.
+
+#endif