fix regression/rlimit-open-files.exe in libc-test

[yunwei37]

syscalls

• add dup syscall
• add support of max open file numbers in process
• support set max open file numbers in prlimit64

minor fix

• fix cd path in readme
• add generate file linux/test-result.txt in gitignore
• readd #[deny(missing_docs)] in linux-object

[coveralls]

Pull Request Test Coverage Report for Build 210593741

• 20 of 37 (54.05%) changed or added relevant lines in 5 files are covered.
• 10 unchanged lines in 5 files lost coverage.
• Overall coverage increased (+0.09%) to 46.671%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
linux-syscall/src/lib.rs	0	1	0.0%
linux-syscall/src/misc.rs	0	3	0.0%
linux-syscall/src/file/fd.rs	3	8	37.5%
linux-object/src/process.rs	15	23	65.22%

Files with Coverage Reduction	New Missed Lines	%
linux-syscall/src/lib.rs	1	44.0%
linux-object/src/process.rs	2	57.46%
linux-syscall/src/file/fd.rs	2	83.33%
../../../../../usr/share/rust/.cargo/registry/src/git.colasdn.top-1ecc6299db9ec823/bitflags-1.2.1/src/lib.rs	2	42.45%
linux-syscall/src/misc.rs	3	44.32%

Totals
Change from base Build 209890495:	0.09%
Covered Lines:	6533
Relevant Lines:	13998

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 210593741

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 20 of 37 (54.05%) changed or added relevant lines in 5 files are covered.
• 10 unchanged lines in 5 files lost coverage.
• Overall coverage increased (+0.09%) to 46.671%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
linux-syscall/src/lib.rs	0	1	0.0%
linux-syscall/src/misc.rs	0	3	0.0%
linux-syscall/src/file/fd.rs	3	8	37.5%
linux-object/src/process.rs	15	23	65.22%

Files with Coverage Reduction	New Missed Lines	%
linux-syscall/src/lib.rs	1	44.0%
linux-object/src/process.rs	2	57.46%
linux-syscall/src/file/fd.rs	2	83.33%
../../../../../usr/share/rust/.cargo/registry/src/git.colasdn.top-1ecc6299db9ec823/bitflags-1.2.1/src/lib.rs	2	42.45%
linux-syscall/src/misc.rs	3	44.32%

Totals
Change from base Build 209890495:	0.09%
Covered Lines:	6533
Relevant Lines:	13998

---

💛 - Coveralls