Enable FTL on Windows

[iangrunert]

Enable FTL on Windows
https://bugs.webkit.org/show_bug.cgi?id=145366

Reviewed by NOBODY (OOPS!).

Enabling webassembly at build time and disabling at runtime, as
FTL makes assumptions that webassembly is enabled. Should be able
to apply a cleaner patch once https://bugs.webkit.org/show_bug.cgi?id=222315
lands (awaiting PR review).

The BBQ JIT won't work on Windows even after the changes for
enabling webassembly on Windows land - it requires changes to GPR
assignment so it can use callee saves. With two fewer GPRs to
work with it runs out of GPRs to assign when running benchmarks.

Currently segfaulting during JetStream2 when running stanford
crypto-aes (on most but not all runs, it occasionally works).

FTL is disabled on Windows for EnumeratorNextUpdateIndexAndMode.
It crashes on Windows with a segfault on a simple test with
JSC_useConcurrentJIT=false. If converted from UGPRPair return
type back to JSValue it works - so either something in the FTL
lowering, or the register allocator is having problems due to the
extra return register required.

```
function getMappedArguments() { return arguments; }

function forIn(object) {
    var keys = [];
    for (var key in object)
        keys.push(key);
    return keys;
}

noInline(forIn);

(function() {
    var mappedArguments = getMappedArguments(0, 1, 2);
    for (var i = 0; i < 1e4; ++i) {
        forIn(mappedArguments);
    }
    print('done');
})();
```

* Source/JavaScriptCore/b3/B3LowerToAir.cpp:
* Source/JavaScriptCore/b3/air/AirCCallSpecial.cpp: (JSC::B3::Air::CCallSpecial::generate):
* Source/JavaScriptCore/b3/air/AirCCallingConvention.cpp:
* Source/JavaScriptCore/b3/air/AirCode.h: (JSC::B3::Air::Code::regsInPriorityOrder const):
(JSC::B3::Air::Code::regsInPriorityOrderImpl):
* Source/JavaScriptCore/b3/air/AirPrintSpecial.h:
* Source/JavaScriptCore/b3/air/opcode_generator.rb:
* Source/JavaScriptCore/b3/air/testair.cpp:
* Source/JavaScriptCore/b3/testb3.h:
* Source/JavaScriptCore/b3/testb3_3.cpp: (correctSqrt):
(testStorePartial8BitRegisterOnX86):
* Source/JavaScriptCore/b3/testb3_4.cpp: (testLoadFromFramePointer):
* Source/JavaScriptCore/ftl/FTLCapabilities.cpp: (JSC::FTL::canCompile):
* Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp: (JSC::FTL::DFG::LowerDFGToB3::compileDelBy):
(JSC::FTL::DFG::LowerDFGToB3::compileMultiGetByOffset): (JSC::FTL::DFG::LowerDFGToB3::compileCompareStrictEq):
* Source/JavaScriptCore/ftl/FTLOSRExitCompiler.cpp: (JSC::FTL::compileStub):
* Source/JavaScriptCore/ftl/FTLOperations.h:
* Source/JavaScriptCore/ftl/FTLOutput.cpp: (JSC::FTL::Output::baseIndex):
* Source/JavaScriptCore/ftl/FTLSlowPathCall.cpp: (JSC::FTL::SlowPathCallContext::SlowPathCallContext):
* Source/JavaScriptCore/jit/RegisterSet.cpp: (JSC::RegisterSetBuilder::ftlCalleeSaveRegisters):
* Source/JavaScriptCore/llint/LLIntData.cpp: (JSC::LLInt::initialize):
* Source/JavaScriptCore/llint/LLIntThunks.cpp: (JSC::LLInt::untaggedPtr):
(JSC::LLInt::inPlaceInterpreterEntryThunk):
(JSC::LLInt::inPlaceInterpreterEntryThunkSIMD):
* Source/JavaScriptCore/llint/LowLevelInterpreter.asm:
* Source/JavaScriptCore/llint/WebAssembly.asm:
* Source/JavaScriptCore/offlineasm/x86.rb:
* Source/JavaScriptCore/runtime/Options.cpp: (JSC::Options::notifyOptionsChanged):
* Source/JavaScriptCore/wasm/WasmB3IRGenerator.cpp: (JSC::Wasm::B3IRGenerator::addI64TruncUF64):
(JSC::Wasm::B3IRGenerator::addI64TruncUF32):
* Source/JavaScriptCore/wasm/WasmBBQJIT.cpp: (JSC::Wasm::BBQJIT::RegisterBinding::none):
(JSC::Wasm::BBQJIT::addI32Rotl):
(JSC::Wasm::BBQJIT::addI64Rotl):
(JSC::Wasm::BBQJIT::addF32ConvertUI32):
(JSC::Wasm::BBQJIT::addF32ConvertUI64):
(JSC::Wasm::BBQJIT::addF64ConvertUI32):
(JSC::Wasm::BBQJIT::addF64ConvertUI64):
(JSC::Wasm::BBQJIT::addF32Copysign):
(JSC::Wasm::BBQJIT::addF64Copysign):
(JSC::Wasm::BBQJIT::addF32Abs):
(JSC::Wasm::BBQJIT::addF64Abs):
(JSC::Wasm::BBQJIT::addF32Neg):
(JSC::Wasm::BBQJIT::addF64Neg):
* Source/JavaScriptCore/wasm/WasmCallee.h:
* Source/JavaScriptCore/wasm/WasmIPIntSlowPaths.cpp: (JSC::LLInt::WASM_IPINT_EXTERN_CPP_DECL):
* Source/cmake/OptionsJSCOnly.cmake:
* Source/cmake/OptionsWin.cmake:

7ea2d98

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
	❌ 🧪 ios-wk2-wpt	❌ 🧪 mac-wk1	❌ 🧪 gtk-wk2
❌ 🛠 🧪 jsc	❌ 🧪 api-ios	❌ 🧪 mac-wk2	❌ 🧪 api-gtk
❌ 🛠 🧪 jsc-arm64	❌ 🛠 tv	❌ 🧪 mac-AS-debug-wk2	❌ 🛠 jsc-armv7
	❌ 🛠 tv-sim	❌ 🧪 mac-wk2-stress	❌ 🧪 jsc-armv7-tests
	❌ 🛠 watch		✅ 🛠 jsc-mips
	❌ 🛠 watch-sim		✅ 🧪 jsc-mips-tests

[webkit-early-warning-system]

EWS run on previous version of this PR (hash e47e709)

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
	❌ 🧪 ios-wk2-wpt	❌ 🧪 mac-wk1	❌ 🧪 gtk-wk2
❌ 🛠 🧪 jsc	❌ 🧪 api-ios	❌ 🧪 mac-wk2	❌ 🧪 api-gtk
❌ 🛠 🧪 jsc-arm64	❌ 🛠 tv	❌ 🧪 mac-AS-debug-wk2	❌ 🛠 jsc-armv7
	❌ 🛠 tv-sim	❌ 🧪 mac-wk2-stress	❌ 🧪 jsc-armv7-tests
	❌ 🛠 watch		✅ 🛠 jsc-mips
	❌ 🛠 watch-sim		✅ 🧪 jsc-mips-tests

[webkit-early-warning-system]

EWS run on previous version of this PR (hash d3cd119)

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
	❌ 🧪 ios-wk2-wpt	❌ 🧪 mac-wk1	❌ 🧪 gtk-wk2
❌ 🛠 🧪 jsc	❌ 🧪 api-ios	❌ 🧪 mac-wk2	❌ 🧪 api-gtk
❌ 🛠 🧪 jsc-arm64	❌ 🛠 tv	❌ 🧪 mac-AS-debug-wk2	❌ 🛠 jsc-armv7
	❌ 🛠 tv-sim	❌ 🧪 mac-wk2-stress	❌ 🧪 jsc-armv7-tests
	❌ 🛠 watch		✅ 🛠 jsc-mips
	❌ 🛠 watch-sim		✅ 🧪 jsc-mips-tests

[webkit-early-warning-system]

EWS run on current version of this PR (hash 7ea2d98)

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
	❌ 🧪 ios-wk2-wpt	❌ 🧪 mac-wk1	❌ 🧪 gtk-wk2
❌ 🛠 🧪 jsc	❌ 🧪 api-ios	❌ 🧪 mac-wk2	❌ 🧪 api-gtk
❌ 🛠 🧪 jsc-arm64	❌ 🛠 tv	❌ 🧪 mac-AS-debug-wk2	❌ 🛠 jsc-armv7
	❌ 🛠 tv-sim	❌ 🧪 mac-wk2-stress	❌ 🧪 jsc-armv7-tests
	❌ 🛠 watch		✅ 🛠 jsc-mips
	❌ 🛠 watch-sim		✅ 🧪 jsc-mips-tests