Streamline dump control options

- Rename `--dump-treei` option to `--dumpi-tree`, which itself is now a
  special case of `--dumpi-<tag>` where tag can be a magic word, or a
  filename
- Control dumping via static `dump*()` functions, analogous to `debug()`
- Make dumping independent of the value of `debug()` (so dumping always
  works even without the debug flag)
- Add separate `--dumpi-graph` for dumping V3Graphs, which is again a
  special case of `--dumpi-<tag>`
- Alias `--dump-<tag>` to `--dumpi-<tag> 3` as before

src/V3Graph.cpp

@@ -28,8 +28,7 @@
 #include <unordered_set>
 #include <vector>
 
-int V3Graph::s_debug = 0;
-int V3Graph::debug() { return std::max(V3Error::debugDefault(), s_debug); }
+VL_DEFINE_DEBUG_FUNCTIONS;
 
 //######################################################################
 //######################################################################
@@ -312,9 +311,7 @@ void V3Graph::dumpEdge(std::ostream& os, V3GraphVertex* vertexp, V3GraphEdge* ed
 }
 
 void V3Graph::dumpDotFilePrefixed(const string& nameComment, bool colorAsSubgraph) const {
-    if (v3Global.opt.dumpTree()) {
-        dumpDotFile(v3Global.debugFilename(nameComment) + ".dot", colorAsSubgraph);
-    }
+    dumpDotFile(v3Global.debugFilename(nameComment) + ".dot", colorAsSubgraph);
 }
 
 //! Variant of dumpDotFilePrefixed without --dump option check