[clang][DeclPrinter] Fix AST print to suppress output of implicit (non-written) constructor initializers

[strimo378]

Summary

DeclPrinter::PrintConstructorInitializers did output non-written constructor initiaizers. In particular, implicit constructor initializers of base classes were output.

[strimo378]

The current output of the test case can be shown here: https://godbolt.org/z/95ToPbqrP

[aaron.ballman]

LGTM!

clang/lib/AST/DeclPrinter.cpp

 }
 
 void DeclPrinter::PrintConstructorInitializers(CXXConstructorDecl *CDecl,
                                                std::string &Proto) {
   bool HasInitializerList = false;
   for (const auto *BMInitializer : CDecl->inits()) {
     if (BMInitializer->isInClassMemberInitializer())
       continue;
+    if (!BMInitializer->isWritten())
+      continue;
 
     if (!HasInitializerList) {
       Proto += " : ";
       Out << Proto;
       Proto.clear();
       HasInitializerList = true;
     } else
       Out << ", ";

clang/test/AST/ast-print-method-decl.cpp

struct DefMethodsWithoutBody {
   // CHECK-NEXT: DefMethodsWithoutBody() = default;
   ~DefMethodsWithoutBody() = default;
 
   // CHECK-NEXT: void m1() __attribute__((alias("X")));
   void m1() __attribute__((alias("X")));
 
   // CHECK-NEXT: };
 };
+
+
+// ---- Check that implict (non-written) constructor initializers are not output
+
+struct ImplicitCtorInit1 {
+  int a;
+};
+
+// CHECK: struct ImplicitCtorInit2 : ImplicitCtorInit1 {
+struct ImplicitCtorInit2 : ImplicitCtorInit1 {
+
+  // CHECK-NEXT: ImplicitCtorInit2(int *) {
+  ImplicitCtorInit2(int *) {
+  // CHECK-NEXT: }
+  }
+
+  // CHECK-NEXT: ImplicitCtorInit2(int **) : ImplicitCtorInit1() {
+  ImplicitCtorInit2(int **) : ImplicitCtorInit1() {
+  // CHECK-NEXT: }
+  }
+
+  // CHECK-NEXT: };
+};