* "Allow ambiguosity of `return` line"
  65b991bc8571b7b718fc22bd33a43c4d269bf52d
* "Move to test/.excludes-prism"
  3b4ff810d2fefdf0194bd774bc04f6f17e2ccae7
* "Pending `EVENT_RETURN` settracefunc tests with Prism"
  a7f33c99c69e3cc62b7a24ce35f51f76cc5bfaa2

This was an optimization for versions prior to 1.9 that traverse the
AST at runtime.

```
1)
TracePoint#inspect returns a String showing the event, method, path and line for a :call event FAILED
Expected "#<TracePoint:call 'call' /tmp/ruby/src/trunk/spec/ruby/core/objectspace/define_finalizer_spec.rb:33>" =~ /\A#<TracePoint:call [`']trace_point_spec_test_call' \/tmp\/ruby\/src\/trunk\/spec\/ruby\/core\/tracepoint\/inspect_spec.rb:43>\z/
to be truthy but was nil
```

This kind of failures comes because of finaizers.
So check the current file or not.

If TracePoint#enable is passed a block, it previously started
the trace on all threads.  This changes it to trace only the
current thread by default.  To limit the scope of the change,
the current thread is only used by default if target and
target_line are both nil.  You can pass target_thread: nil
to enable tracing on all threads, to get the previous
default behavior.

Fixes [Bug #16889]

This updates the trace instructions to directly dispatch to
opt_send_without_block.  So this should cause no slowdown in
non-trace mode.

To enable the tracing of the optimized methods, RUBY_EVENT_C_CALL
and RUBY_EVENT_C_RETURN are added as events to the specialized
instructions.

Fixes [Bug #14870]

Co-authored-by: Takashi Kokubun <takashikkbn@gmail.com>