This avoids external commands from finishing after the TinyGo command
exits. For example, when testing out compiler-rt on AVR, I got the
following error:
$ go install; and tinygo run -target=atmega1284p ./testdata/calls.go
[... Clang error removed ...]
error: failed to build /home/ayke/src/github.com/tinygo-org/tinygo/lib/compiler-rt/lib/builtins/extendsfdf2.c: exit status 1
error: unable to open output file '/tmp/tinygo361380649/build-lib-compiler-rt/ffsdi2.c.o': 'No such file or directory'
1 error generated.
That last error ("unable to open output file") is a spurious error
because the temporary directory has already been removed. This commit
waits until all running jobs have finished before returning, so that
these errors won't happen.
ab41c79de7