Reference:
  https://medium.com/@alexey.inkin/how-to-force-newline-at-end-of-files-and-why-you-should-do-it-fdf76d1d090e

The egrep command has been deprecated since 2007. Beginning with GNU
grep 3.8, calling the command will now issue a warning to the user that
instead they should use 'grep -E'.

The time complexity checks on certain functions might fail, and it is
not worth proceeding in provisioning profiles since we expect to shorten
CI pipeline.

Due to the lack of foreseen solutions, the official repository has
been failing the CI pipeline for a lengthy long period. It raises the
risk that CI will not be able to identify integration issues as soon
as possible. With the help of the deploy key, this patch pulls a unique
"provisioning profile" from a private repository. As a result, it is
allowed to examine the official repository without potentially
disclosing the solutions in forked ones.

In original CMU assignment, a singly-linked list was used. However,
toward to Linux kernel development, we would like to stick to its linked
list implementation. That is, we take the circular doubly-linked list to
re-implement the queue oriented operations. In addition, we introduce
some LeetCode exercises based on Linux-like lists.

Now, queue is replaced with linux kernel linked list. Also, implementation
of l_new, l_free, l_insert_head, l_insert_tail, l_remove_head and l_size
are added.

Implementation of l_sort and l_reverse are added.

Add command "mid" which would return the middle element in list.
Relative test also be added in this commit

Add command "swap" which would swap every two adjacent nodes in list.
Relative test also be added in this commit.
Reference:
    https://leetcode.com/problems/swap-nodes-in-pairs/

Replace "get_mid" with "remove_mid", which is LeetCode problem.
Relative test bench also be updated in this commit.
Reference:
    https://leetcode.com/problems/delete-the-middle-node-of-a-linked-list/



Add command remove_tail.

Suppress the null pointer errors

Newer versions of cppcheck find the potential NULL pointer
bug in list_entry. The function is difficult to refactor without
extensive work, so suppress the potential NULL pointer error
which cannot occur for now.

remove_tail and remove_head was re-desinged. We extract "free" from
remove_.* because "free" is not stable (lead not constant time).
Relative testbench also update in this commit.

Add function "is_circular" which check if the queue is doubly circular.

Suppress simulation of list removal on Arm64

We suffered from some unknown issues that simulation of list removal can
not pass on Arm64 based platforms such as ThunderX2/Linux and Apple M1
(macOS).

At the moment, we just skip the simulations for Arm64.

We support new command: dedup.
Relative test bench also be updated.

Co-authored-by: eecheng87 <yucheng871011@gmail.com>