Fix ms type_info to be a 'class' type

It was brought up on #151277 that the patch changes type_info from class
to struct. While I couldn't find a way to test/notice this, this patch
changes it to a class.

While I'm here, I am also removing unnecessary/against coding standard
curley brackets.

Author: erichkeane

clang/include/clang/AST/ASTContext.h

@@ -2394,9 +2394,8 @@ class ASTContext : public RefCountedBase<ASTContext> {
   /// Retrieve the implicitly-predeclared 'struct type_info' declaration.
   TagDecl *getMSTypeInfoTagDecl() const {
     // Lazily create this type on demand - it's only needed for MS builds.
-    if (!MSTypeInfoTagDecl) {
-      MSTypeInfoTagDecl = buildImplicitRecord("type_info");
-    }
+    if (!MSTypeInfoTagDecl)
+      MSTypeInfoTagDecl = buildImplicitRecord("type_info", TagTypeKind::Class);
     return MSTypeInfoTagDecl;
   }