remove file_exists check from Module_js.Node.parse_main

Summary: I don't think we need this check. when it was written, we would error if we tried to look up a package that wasn't in the heap. these days, `get_package` returns `None` and all is fine. we should avoid hitting the disk here; it's cheaper to test the shared hash table than to do a `file_exists` check on eden.

Reviewed By: samwgoldman

Differential Revision:
D35805594 (facebook@50f738c)

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(from 7b9480546bb83a21729f0c4e42f477025146e6d0)

fbshipit-source-id: 19f338912a3fd41b60c2e5d434b7f1c7b82ff466

v0.176.2

Summary: happyflow

Reviewed By: mroch

Differential Revision:
D35666938 (facebook@a9c21ca)

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(from 194828e28a5dd8e06864661a1bd323a3c10a34e0)

fbshipit-source-id: b0982edabfd0f68812c358a9a0da10307182eed5

v0.176.1

Summary: hannah_is_flow_owo

Reviewed By: samwgoldman

Differential Revision:
D35626225 (facebook@1c0e24f)

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(from c6a0c66bb92fa9136be1f5fd2b1a2ba236786a21)

fbshipit-source-id: c4cd7cdb0436d1b30bad6042e7f2a35686342074

v0.176.0

Reviewed By: samwgoldman, SamChou19815

Differential Revision:
D35592859 (facebook@9486c40)

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(from 1ee02b9af2ae9286ed6770d22c8192904ab992f8)

fbshipit-source-id: 0e9327dd9f9a390c4153e9e76375b016820983e3

v0.175.1

Summary: (Note: this ignores all push blocking failures!)

Reviewed By: SamChou19815

Differential Revision:
D35415611 (facebook@71e6557)

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(from 85285188a29ef94633931988dda505024ebfa78e)

fbshipit-source-id: cb40b76acb336b35a736ff32d5a2bb8f51737367

pin to core_kernel 0.14.x

Summary:
Pull Request resolved: facebook#8869

core_kernel 0.15 adds a deprecation warning about being renamed to Core, which we treat as an error.

since we're pinned on 0.14 internally, i'm doing the same on github for now. ideally, we'd use an opam lock file to pin all of our dependencies.

Reviewed By: jbrown215

Differential Revision: D35283155

fbshipit-source-id: c253268501b14ff00aea53d0295f0d78468e7f63

v0.174.1

Summary: (Note: this ignores all push blocking failures!)

Reviewed By: pieterv, bradzacher

Differential Revision:
D34973154 (facebook@8eede28)

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(from bebccc067ea47455af4da536ff8d2bfff2c085bc)

fbshipit-source-id: 64bde5107a17d5d88cb493fbe823896111e35a68

v0.174.0

Summary: flow_errors_everywhere

Reviewed By: evanyeung

Differential Revision: D34932617

fbshipit-source-id: 02b3d937f8c20e00149bb528609eaf9dc761b945

v0.173.0

Reviewed By: mroch, pieterv

Differential Revision: D34588851

fbshipit-source-id: b758532059d6d80d62706b758096e1afd491c144

v0.172.0

Reviewed By: panagosg7

Differential Revision: D34278525

fbshipit-source-id: 5e0c15ee876f6ba81fda1f6015284d43de3d2ab3