Use createError in JSError and forward it in RuntimeDecorator (#58961)

[lavenzg]

Summary:

JSError(rt, message) still creates its value by looking up globalThis.Error and calling it, which predates IRuntime::createError. It now uses rt.createError(...) like the JSError::createXError factories, with the same try/catch fallback. The default Runtime::createError makes the same global call, so runtimes without a native implementation behave as before. On Hermes every JSError thrown from native code skips a global lookup and a JS call, and message, stack and what() come out the same.

RuntimeDecorator and WithRuntimeDecorator didn't forward the createError family, so decorated runtimes (the thread-safe runtime, TracingRuntime) quietly fell back to the global constructor calls. They forward to plain() now, through Around for WithRuntimeDecorator, and they're public like in jsi::Runtime.

One visible difference on Hermes, same as the other createXError APIs: if user code replaced or deleted globalThis.Error, JSError(rt, message) no longer calls the replacement and creates a real Error anyway.

X-link: facebook/hermes#2203

Test Plan:
Two new tests in testlib.cpp. JSErrorMessageTest checks the value is an Error with the right message and a string stack, and that a counting globalThis.Error replacement gets called exactly as often as rt.createError calls it, so it holds for native and default implementations. DecoratorCreateErrorTest checks that all seven createXError calls, and JSError, reach the wrapped runtime once through both decorators, and that Around runs once.

JSErrorDoesNotInfinitelyRecurse and CreateJSErrorPropagatesOOMExceptionTest run through decorators that use the default Runtime::createError. This keeps the missing-constructor fallback and OOM propagation covered, since both tests depend on changing globalThis.Error.

APITests (ASan + Debug, macOS arm64, HERMESVM_EXCEPTION_ON_OOM=ON): 362/362 pass, including SynthTrace and all three OOM tests. Built with -O1 and HERMES_ENABLE_WERROR=ON; the existing GoogleTest uninitialized-const-pointer warning is demoted for AppleClang 21.

cmake --build cmake-build-asan-oom --target APITests -j 8
cmake-build-asan-oom/unittests/API/APITests

Before the OOM test adaptation, CreateJSErrorPropagatesOOMExceptionTest fails because it throws JSError instead of JSOutOfMemoryError. It passes with the decorator. The earlier checks with the jsi.cpp and decorator.h changes reverted also made the new JSI tests fail.

Reviewed By: javache

Differential Revision: D124178378

Pulled By: lavenzg

[meta-codesync]

@lavenzg has exported this pull request. If you are a Meta employee, you can view the originating Diff in D124178378.

[meta-codesync]

@lavenzg merged this pull request in 0cca3a1.