Backport of llvmPackages_10 since Chromium 83 will depend on it.
See NixOS/nixpkgs#83350 (comment)

llvmPackages_10: copy llvmPackages_9

* starting with rc2
* make `lldb` compilable again on Darwin
* separate out manpage creation for `lldb` into a new derivation
* minor tweaks to the patching of sources,
  some of which are backportable to earlier versions

(cherry picked from commit f111c6f)

llvmPackages_10: rc2 -> rc3

http://lists.llvm.org/pipermail/llvm-dev/2020-March/139729.html

Additionally cherry-picked 3 commits from `llvm-project/master`:
- llvm/llvm-project@d21664c
- llvm/llvm-project@3a0f6e6
- llvm/llvm-project@87dac7d

such that clang can automatically pick up the polly plugin from the
`llvm-polly` build.

(cherry picked from commit 3a84353)

llvmPackages_10: rc3 -> rc4

Only needed to update hashes and the version.
Updated comment for extension handling patch

(cherry picked from commit 0ec3f4e)

llvmPackages_10: removed extra polly-build

There is no good reason to have separate builds for polly and no-polly
versions. wwwwwThe reason for the two versions was (as far as I can
tell) to defer rebuilds (see ed60483).
Polly is now enabled by default.

(cherry picked from commit e9aa877)

llvmPackges_10: rc4 -> rc5

updated versino and hashes for new rc

(cherry picked from commit cdee144)

llvmPackages_10: rc5 -> release

updated hashes and url
updated comment regarding version/release_version to make it clearer

(cherry picked from commit 4665b2a)

[20.03] llvmPackages_10: init at 10.0.0

This is a backport to support building stable firefox version on the
stable release channel. Firefox has some very strict requirements on
it's dependencies. Since we do not want to use bundled versions of
dependencies this backport is required fore Firefox >=74.

This is a backport to support building stable firefox version on the
stable release channel. Firefox has some very strict requirements on
it's dependencies. Since we do not want to use bundled versions of
dependencies this backport is required fore Firefox >=74.

https://github.com/sagiegurari/cargo-make/releases/tag/0.30.2
(cherry picked from commit 268f71c)

Allow build pass by disabling test. Isolated issue to
test_sockets.py::TestAIOSockets::test_sock_close_add_reader_race.
This test is supposed to be skipped, but it isn't for some reason,
so we disable it instead.
See uvloop#284 (MagicStack/uvloop#284)
for full details. Don't know why this test isn't properly skipped.

(cherry picked from commit 364909d)

[20.03]: python38Packages.uvloop: enable build

https://bugs.kde.org/show_bug.cgi?id=417316
(cherry picked from commit 18539b1)

(cherry picked from commit 1af6a1a)
This fixes a crash when opening the file picker.

https://github.com/tulir/mautrix-telegram/releases/tag/v0.7.2
(cherry picked from commit 1c54edc)

for the third time...

(cherry picked from commit df594f1)

[20.03] update firefox to latests stable (secure) release

(cherry picked from commit 119a7aa)