debugger: don't set the `repl.prompt` string

It wasn't doing anything, and actually due to
3ae0b17c76f693dd2e68a46f78c7dc7f595b33c6, it was causing
the readline `prompt()` function to be overwritten
which throws an error in the REPL shortly after.
src: remove `node_isolate` from source

fix #6899
node_internals: add missing env-inl.h include
tracing: update to dtrace-provider style emission

Remove the last vestiges of macros from the JavaScript portion of the
build system.

Implement tracing module, allow basic registration of static probes
previously defined for dtrace/etw/systemtap to be expressed in these
primitives.
src: add dtrace-provider into core
support namespaces
add dtrace-provider style to tracing
refactor into Probe being a thing
make binding simpler without needing a closure
add marshalling support
clean up