Non-unified build with LLD fails due to undefined AuxiliaryBarrier<JSC::Butterfly*> constructor

[Adrian Perez]

From https://build.webkit.org/#/builders/133/builds/13263/steps/10/logs/errors

---- 8< ----

ld.lld: error: undefined symbol: JSC::AuxiliaryBarrier<JSC::Butterfly*>::AuxiliaryBarrier<JSC::Butterfly*&>(JSC::VM&, JSC::JSCell*, JSC::Butterfly*&)
collect2: error: ld returned 1 exit status

[Adrian Perez]

JFTR, given that the linker error is all but useful, I ended up using
the following big hammer 🔨️ approach to find which .o file had an
undefined reference to the inline:

  % nm -PCul WebKitBuild/GTK/Debug/Source/JavaScriptCore/**/*.o \
      | grep AuxiliaryBarrier
 JSC::AuxiliaryBarrier<JSC::Butterfly*>::AuxiliaryBarrier<JSC::Butterfly*&>(JSC::VM&, JSC::JSCell*, JSC::Butterfly*&)  U    WebAssemblyArrayPrototype.cpp:0

Scanning all the object files works because, as an inline, the undefined
function implementation should have been inlined into each object file
that needs it, instead of resulting in an undefined symbol 😉️

Patch incoming...

[Adrian Perez]

Pull request: https://github.com/WebKit/WebKit/pull/5374

[EWS]

Committed 255536@main (f76663a6c9ce): <https://commits.webkit.org/255536@main>

Reviewed commits have been landed. Closing PR #5374 and removing active labels.

[Radar WebKit Bug Importer]

<rdar://problem/101175334>