Core: Modernize

modernize-use-auto
modernize-use-nullptr
modernize-use-override
modernize-use-using
modernize-use-default-member-init (partially)

Change-Id: Idf10d7ffb1d98a04edc09a25c35e4e9e3abe87b5
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/coreplugin/id.cpp

@@ -56,9 +56,7 @@ namespace Core {
 class StringHolder
 {
 public:
-    StringHolder()
-        : n(0), str(0)
-    {}
+    StringHolder() = default;
 
     StringHolder(const char *s, int length)
         : n(length), str(s)
@@ -72,8 +70,8 @@ public:
             h &= 0x0fffffff;
         }
     }
-    int n;
-    const char *str;
+    int n = 0;
+    const char *str = nullptr;
     quintptr h;
 };