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/035lookup.cc b/035lookup.cc
index 02c2ab3f..b7c05201 100644
--- a/035lookup.cc
+++ b/035lookup.cc
@@ -88,7 +88,7 @@ void lookup_memory(reagent& x) {
 void lookup_memory_core(reagent& x, bool check_for_null) {
   double address = x.value + /*skip alloc id in address*/1;
   double new_value = get_or_insert(Memory, address);
-  trace("mem") << "location " << address << " contains " << no_scientific(new_value) << end();
+  trace(Callstack_depth+1, "mem") << "location " << address << " contains " << no_scientific(new_value) << end();
   // check for null
   if (check_for_null && new_value == 0) {
     if (Current_routine) {