4987 - support `browse_trace` tool in SubX

I've extracted it into a separate binary, independent of my Mu prototype.

I also cleaned up my tracing layer to be a little nicer. Major improvements:

- Realized that incremental tracing really ought to be the default.
  And to minimize printing traces to screen.

- Finally figured out how to combine layers and call stack frames in a
  single dimension of depth. The answer: optimize for the experience of
  `browse_trace`. Instructions occupy a range of depths based on their call
  stack frame, and minor details of an instruction lie one level deeper
  in each case.

Other than that, I spent some time adjusting levels everywhere to make
`browse_trace` useful.

1 files changed, 1 insertions, 1 deletions

diff --git a/subx/038---literal_strings.cc b/subx/038---literal_strings.cc
index 7077a685..ce46a119 100644
--- a/subx/038---literal_strings.cc
+++ b/subx/038---literal_strings.cc
@@ -23,7 +23,7 @@ Transform.push_back(transform_literal_strings);
 int Next_auto_global = 1;
 :(code)
 void transform_literal_strings(program& p) {
-  trace(99, "transform") << "-- move literal strings to data segment" << end();
+  trace(3, "transform") << "-- move literal strings to data segment" << end();
   if (p.segments.empty()) return;
   segment& code = p.segments.at(0);
   segment data;