Fix result height when folding select in WasmBBQJIT

[ddegazio]

c0310d3

Fix result height when folding select in WasmBBQJIT
https://bugs.webkit.org/show_bug.cgi?id=253592
rdar://106420016

Reviewed by Michael Saboff and Yusuke Suzuki.

Currently, when BBQ JIT folds a select instruction, it naively selects
between the Value operands it was given based on the constant condition.
This can sometimes result in a resulting temp with an incorrect stack
height.

This patch changes select to consume all operands, not just the one we
didn't select, similar to the non-folded case. It also sets the result
to the right temp index, if applicable (we can still return a constant,
where the height of the value is irrelevant), and allocates it
independently. Finally, this patch also includes some semi-related
changes to the BBQ JIT move helpers, allowing them to be used to move
values between any two Locations, instead of the current implementation
which requires the source operand to be a Value.

* JSTests/wasm/stress/foldable-select.js: Added.
(async test):
* Source/JavaScriptCore/wasm/WasmBBQJIT.cpp:
(JSC::Wasm::BBQJIT::addSelect):
(JSC::Wasm::BBQJIT::emitStore):
(JSC::Wasm::BBQJIT::emitMoveMemory):
(JSC::Wasm::BBQJIT::emitMoveRegister):
(JSC::Wasm::BBQJIT::emitLoad):
(JSC::Wasm::BBQJIT::emitMove):

Canonical link: https://commits.webkit.org/261461@main

7253ec2

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	🧪 gtk-wk2
✅ 🛠 🧪 jsc	✅ 🛠 tv	✅ 🧪 mac-wk2	🧪 api-gtk
✅ 🛠 🧪 jsc-arm64	✅ 🛠 tv-sim	❌ 🧪 mac-AS-debug-wk2	✅ 🛠 jsc-armv7
	✅ 🛠 watch	✅ 🧪 mac-wk2-stress	✅ 🧪 jsc-armv7-tests
✅ 🛠 🧪 merge	✅ 🛠 watch-sim		✅ 🛠 jsc-mips
			✅ 🧪 jsc-mips-tests

[webkit-early-warning-system]

EWS run on current version of this PR (hash 7253ec2)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	🧪 gtk-wk2
✅ 🛠 🧪 jsc	✅ 🛠 tv	✅ 🧪 mac-wk2	🧪 api-gtk
✅ 🛠 🧪 jsc-arm64	✅ 🛠 tv-sim	❌ 🧪 mac-AS-debug-wk2	✅ 🛠 jsc-armv7
	✅ 🛠 watch	✅ 🧪 mac-wk2-stress	✅ 🧪 jsc-armv7-tests
✅ 🛠 🧪 merge	✅ 🛠 watch-sim		✅ 🛠 jsc-mips
			✅ 🧪 jsc-mips-tests

[msaboff]

r=me

[webkit-commit-queue]

Committed 261461@main (c0310d3): https://commits.webkit.org/261461@main

Reviewed commits have been landed. Closing PR #11247 and removing active labels.