fix deadlock in RCU retire when rcu_reader active

Summary:
Every 3.2 seconds RCU retire tries to opportunistically
drain the queue of pending work.  If this happens while
the current thread is holding an rcu_reader and another
thread is currently running synchronize(), a deadlock will
occur.  This diff adds a unit test for the behavior and
fixes the problem.

Test Plan:
* unit test that reproduces the problem
* unit test passes with the fix

Change Hazptr internal set type to folly container

Summary: `F14FastSet` strictly superior.

Reviewed By: ot

Differential Revision: D42533179

fbshipit-source-id: 624bc544de5e1c82a4ca983e21599c1411c7f54d

Expand CpuId for more AVX512 support

Summary: Also add a way to check the vendor string.

Reviewed By: mattjgalloway

Differential Revision: D43925665

fbshipit-source-id: 2f66e5d573567c5b0fda5d7c27e4587439cab8fe

Rm implementation-detail test

Summary: After discussion with ot, we agree that this diff is only testing implementation details, and based on D45446476 those details are impractical to test. The obvious result: delete the test.

Reviewed By: ot

Differential Revision: D45571582

fbshipit-source-id: 5f5c11ef22c87ecb91830104feb5d0215e19b9fb

Add Dictionary Encoded vectors to PyVelox (#3859)

Summary:
This PR adds support for dictionary vectors in PyVelox. Currently base vectors are supported only for primitive (physical) types , and this also thus extends to Dictionary vectors.
Dictionary vectors are required for additional fuzzer support, and expression eval in pyvelox.

X-link: facebookincubator/velox#3859

Reviewed By: pedroerp

Differential Revision: D45409925

Pulled By: kgpai

fbshipit-source-id: 6b05a0d543332fea48d912f93f267896d005f4e2

Add sorted_vector_set::const_pointer (facebook#1987)

Summary:
Pull Request resolved: facebook#1987

similarly, `std::set` has const_pointer

Reviewed By: swolchok

Differential Revision: D45194122

fbshipit-source-id: 5ad1b7c40fb21a92333603d804ee2e3f16c78f27

fix deadlock in RCU retire when rcu_reader active

Summary:
Every 3.2 seconds RCU retire tries to opportunistically
drain the queue of pending work.  If this happens while
the current thread is holding an rcu_reader and another
thread is currently running synchronize(), a deadlock will
occur.  This diff adds a unit test for the behavior and
fixes the problem.

Test Plan:
* unit test that reproduces the problem
* unit test passes with the fix

folly | Fix inconsistent-missing-destructor-override warnings

Summary:
changelog: [internal]

Fixing inconsistent use of 'override' in destructors.

Reviewed By: nlutsenko

Differential Revision: D44942816

fbshipit-source-id: 8d0c143e268edd3ece28baa821a6ec51a2ec38e3

CacheLocalityTest.Basic on Windows

Summary:
max_align_t is usually 8 on Windows, so fix this unit test which
assumes 16-byte alignment.

Reviewed By: Orvid

Differential Revision: D44726286

fbshipit-source-id: 3662000c4e55177d690d3aeb47fed817812ec893

fix lazy serialization performance in pathological case

Summary:
`rewriteDouble()` currently walks the whole output queue, which means
in a pathological case of serializing container of lazy objects we get
accidentally quadratic performance.

Reviewed By: luciang

Differential Revision: D44607256

fbshipit-source-id: 4072a1f76c97d37089aa97b1f419d78a3701a38b