[OpenMP] Fix building for 32-bit DragonFly, NetBSD, OpenBSD (#70527)

Fixing ```#error "Unknown or unsupported OS"```

Author: brad0

openmp/runtime/src/kmp_runtime.cpp

@@ -8925,7 +8925,8 @@ __kmp_determine_reduction_method(
 
 #elif KMP_ARCH_X86 || KMP_ARCH_ARM || KMP_ARCH_AARCH || KMP_ARCH_MIPS
 
-#if KMP_OS_LINUX || KMP_OS_FREEBSD || KMP_OS_WINDOWS || KMP_OS_HURD
+#if KMP_OS_LINUX || KMP_OS_DRAGONFLY || KMP_OS_FREEBSD || KMP_OS_NETBSD ||     \
+    KMP_OS_OPENBSD || KMP_OS_WINDOWS || KMP_OS_HURD
 
     // basic tuning