feature/spaceship: Merge LLVM update#1615

Merged

StephanTLavavej merged 14 commits intomicrosoft:feature/spaceshipfrom

StephanTLavavej:merge_spaceship

Feb 3, 2021

Commits on Jan 26, 2021

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Commits on Jan 31, 2021

P0466R5 Layout-Compatibility And Pointer-Interconvertibility Traits (#1575)

MahmoudGSaleh
and
StephanTLavavej
authored

Commits on Feb 1, 2021

<chrono>: Partially implement P0355R7 (#323)

authored

Commits on Feb 2, 2021

<xmemory>: remove deprecated std::allocator members in C++20 (#1585)
Michael S. Rizkalla
authored
Update LLVM submodule reference (#1594)

CaseyCarter
and
StephanTLavavej
authored