Upstream changes from local DocTest source code to the origin repository

[ivankochin]

Now the DocTest is updated to the latest version (2.4.6) but it still has several local fixes that were not upstreamed to the origin repository. This should be done to simplify the future DocTestupdating process. Here is the list of local changes with the comments:

Possibly already fixed in the origin repo issues (dev branch):

• Fix copy elision absence case - (Fix the logic that depends on optional copy elision optimization doctest/doctest#516)
• Implement old version of check due to Intel Compiler internal error: assertion failed at: "shared/cfe/edgcpfe/exprutil.c", line 5155 -(Fixed intel compiler parser bug. Should fix #502 doctest/doctest#523)
• Fix the typo (word "degrade") - (Spelling doctest/doctest#546)

Fixes that have the corresponding PR to the origin repo:

• list_query_results() was declared but never referenced - (Remove unused list_query_results() function doctest/doctest#550)

Fixes that may be upstreamed without additional actuality check:

• Universal Windows Platform support - (Add Universal Windows Platform support doctest/doctest#558)

Fixes that should be reviewed before the upstreaming:

• Intel Compiler support
  • Work-around for the warning: 'routine is both "inline" and "noinline"'
• missing initializer for member - (Fix error: missing initializer for member doctest::detail::TestSuite doctest/doctest#556)
• Due to race between exiting the process and starting of a new detached thread in Windows, thread local variables, which constructors or destructors have calls to runtime functions (e.g. free() function) can cause access violation since TBB along with runtime library may have been unloaded by the time these variables are constructed or destroyed.
• DOCTEST_ANONYMOUS doesn't work on the same line here on MSVS 15.9.13 - (Fix error: missing initializer for member doctest::detail::TestSuite doctest/doctest#556)

All the changes listed above are marked inside our local DocTest source code by the "TODO: upstream the change to doctest : ..." comments.

[nofuturre]

@ivankochin is this issue still relevant?

[isaevil]

@nofuturre It is. We are still applying workarounds to doctest while doing updates. But I think we need to check if is there any issues with the latest version.