Allow preprocessor to extract sequence of commands

[angelhof]

Use by running the following when on $PASH_TOP.

./compiler/preprocessor/preprocessor spec input.sh partial_order.sh

It will save a sequence of commands in partial_order.sh.

For now it is very janky since it prints each command in its own line (but this can fail very badly if commands contain newlines).

TODO: We need to fix this to print each command in its own file, and the partial order file should only contain the ids of the commands and their ordering. I need to add a new directory speculation in compiler, that will contain relevant code.

[angelhof]

@gliargovas this should be helpful for you!

[github-actions]

OS:ubuntu-20.04
Tue Feb 28 00:23:17 UTC 2023
intro: 2/2 tests passed.
interface: 39/39 tests passed.
compiler: 54/54 tests passed.
agg: 109/109 tests passed.

[github-actions]

OS = Debian 10
CPU = Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz
Ram = 15752
Hash = de6b3cf
Kernel= Linux 4.15.0-197-generic x86_64

benchmark	tests	passed	failed	untested	unresolved	unsupported	not_in_use	other_status
posix	494	375	41	31	6	40	1	0
intro	2	2	0	0	0	0	0	0
interface	39	39	0	0	0	0	0	0
compiler	54	54	0	0	0	0	0	0
aggregator	109	109	0	0	0	0	0	0