os_windows.obj : error LNK2019: unresolved external symbol "public: void __thiscall Semaphore::wait_with_safepoint_check(class JavaThread *)" (?wait_with_safepoint_check@Semaphore@@QAEXPAVJavaThread@@@Z) referenced in function "int __cdecl check_pending_signals(void)" (?check_pending_signals@@YAHXZ)

d:\priv\openjdk\nb\ntintel\jdk-build-fastdebug\support\modules_libs\java.base\server\jvm.dll : fatal error LNK1120: 1 unresolved externals

The error is just a missing include. I have no idea why this only breaks x86 though. It has nothing to do with different calling conventions between caller and callee (a typical pain point on x86 windows). Atm I just assume the Windows x64 build pulls semaphore.inline.hpp via some other includes.