Internals: More const. No functional change intended.

src/V3Name.cpp

@@ -37,7 +37,7 @@ private:
     //  AstCell::user1()        -> bool.  Set true if already processed
     //  AstScope::user1()       -> bool.  Set true if already processed
     //  AstVar::user1()         -> bool.  Set true if already processed
-    AstUser1InUse m_inuser1;
+    const AstUser1InUse m_inuser1;
 
     // STATE
     AstNodeModule* m_modp = nullptr;