This implements the spec change in
https://github.com/tc39/ecma262/pull/2164

Making TA elements configurable has interaction with delete. While
the elements are configurable, they are only "deletable" via detaching
the underlying ArrayBuffer, not via `delete`. That is, `delete ta[idx]`
for an in-bounds `idx` still returns false.

Bug: v8:11281
Change-Id: I2e9348a7ec3c3239a92cc35e51b7182423736834
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2605234Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71955}

With bytecode flushing and lazy feedback allocation, we need to call
%PrepareForOptimization before we call %OptimizeFunctionOnNextCall,
ideally after declaring the function.

Bug: v8:8801, v8:8394, v8:9183
Change-Id: I3fb257282a30f6526a376a3afdedb44786320d34
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1648255
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62119}

TypedArrays need specific checks before calling OrdinaryDefineOwnProperty.

BUG=v8:5328

Review-Url: https://codereview.chromium.org/2431223005
Cr-Commit-Position: refs/heads/master@{#41333}

Previously, fast holey elements accessors would detect element presence
by simply doing a hole check on any slot within the backing store's
capacity. This relied on the (mostly-true but brittle) assumption that
slots beyond the length are always correctly zapped with The Hole.

Review-Url: https://codereview.chromium.org/2297253002
Cr-Commit-Position: refs/heads/master@{#39051}

BUG=v8:4137
LOG=n

Review URL: https://codereview.chromium.org/1238533003

Cr-Commit-Position: refs/heads/master@{#29645}