Clean up trivial default constructors now.

hasTrivialDefaultConstructor() really really means it now.

Also implement a fun standards bug regarding aggregates. Doug, if you'd
like, I can un-implement that bug if you think it is truly a defect.

The bug is that non-special-member constructors are never considered
user-provided, so the following is an aggregate:

struct foo {
  foo(int);
};

It's kind of bad, but the solution isn't obvious - should

struct foo {
  foo (int) = delete;
};

be an aggregate or not?

Lastly, add a missing initialization to FunctionDecl.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@131101 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index 775b1d1..db8d29c 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -534,7 +534,7 @@
     return;
 
   // If the default constructor has not yet been declared, do so now.
-  if (!Class->hasDeclaredDefaultConstructor())
+  if (!Class->needsImplicitDefaultConstructor())
     DeclareImplicitDefaultConstructor(Class);
 
   // If the copy constructor has not yet been declared, do so now.
@@ -581,7 +581,7 @@
     if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
       if (Record->getDefinition() &&
           CanDeclareSpecialMemberFunction(S.Context, Record)) {
-        if (!Record->hasDeclaredDefaultConstructor())
+        if (!Record->needsImplicitDefaultConstructor())
           S.DeclareImplicitDefaultConstructor(
                                            const_cast<CXXRecordDecl *>(Record));
         if (!Record->hasDeclaredCopyConstructor())
@@ -2140,7 +2140,7 @@
 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
   // If the copy constructor has not yet been declared, do so now.
   if (CanDeclareSpecialMemberFunction(Context, Class)) {
-    if (!Class->hasDeclaredDefaultConstructor())
+    if (!Class->needsImplicitDefaultConstructor())
       DeclareImplicitDefaultConstructor(Class);
     if (!Class->hasDeclaredCopyConstructor())
       DeclareImplicitCopyConstructor(Class);