make mkdir_p spit out world-readable directories
Summary:
This is super strange. `mkdir_p` uses 0770 and `mkdir_no_fail` uses 0777
for the directory permissions. It appears that
D3691691 incorrectly created `mkdir_p`;
before that diff, they would have been 0770. This impacts `flow` compiler: the
recursive artifact output is not world-readable, so stuff written by the compiler
is not readable by the webserver user.
Reviewed By: alexchow
Differential Revision:
D6044487
fbshipit-source-id:
b6ba1c096c53adc43b51cdd45e91063ee5f9ea93