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/V3EmitCConstPool.cpp

@@ -27,6 +27,8 @@
 #include <algorithm>
 #include <cinttypes>
 
+VL_DEFINE_DEBUG_FUNCTIONS;
+
 //######################################################################
 // Const pool emitter
 
@@ -38,7 +40,6 @@ class EmitCConstPool final : public EmitCConstInit {
     VDouble0 m_constsEmitted;
 
     // METHODS
-    VL_DEBUG_FUNC;  // Declare debug()
 
     V3OutCFile* newOutCFile() const {
         const string fileName = v3Global.opt.makeDir() + "/" + topClassName() + "__ConstPool_"