Internals: Standardize debug() function generation. No functional change intended.

src/V3LinkLValue.cpp

@@ -47,11 +47,7 @@ private:
     AstNodeFTask* m_ftaskp;	// Function or task we're inside
 
     // METHODS
-    static int debug() {
-	static int level = -1;
-	if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__);
-	return level;
-    }
+    VL_DEBUG_FUNC;  // Declare debug()
 
     // VISITs
     // Result handing