Add debug logging facility to track waits on external processes when EM_BUILD_VERBOSE >= 3. This helps pinpointing if the build hangs on some tool dying/live/deadlocking, and where it might occur.
Implement process.pid on WindowsPopen replacement so that EM_BUILD_VERBOSE=3 works on it as well.
- made test_stdin async to work in the node environment
- clearerr should reset both eof and error indicators
- fgetc was incorrectly setting the eof indicator. in cases where fread had errored with EAGAIN it was setting eof. I removed the set entirely, as there is no need for fgetc to even worry about it, fread will set the correct value in any case
Alon Zakai
Jukka Jylänki
Anthony Pesch
Chad Austin