Internals: Minor cleanups preparing for initialization fixes. No functional change.

src/V3AstNodeDType.h

@@ -291,7 +291,7 @@ public:
     VNumRange declRange() const VL_MT_STABLE { return VNumRange{hi(), lo()}; }
     AstNodeModule* classOrPackagep() const { return m_classOrPackagep; }
     void classOrPackagep(AstNodeModule* classpackagep) { m_classOrPackagep = classpackagep; }
-    bool isConstrainedRand() { return m_constrainedRand; }
+    bool isConstrainedRand() const { return m_constrainedRand; }
     void markConstrainedRand(bool flag) { m_constrainedRand = flag; }
 };