[openmp] Silence warning when compiling with MSVC targetting x86

This fixes:
```
[3593/7449] Building CXX object projects\openmp\runtime\src\CMakeFiles\omp.dir\kmp_debug.cpp.obj
C:\git\llvm-project\openmp\runtime\src\kmp_os.h(471): warning C4163: '_InlineInterlockedExchange64': not available as an intrinsic function
```

openmp/runtime/src/kmp_os.h

@@ -467,7 +467,7 @@ enum kmp_mem_fence_type {
 #pragma intrinsic(InterlockedExchangeAdd)
 #pragma intrinsic(InterlockedCompareExchange)
 #pragma intrinsic(InterlockedExchange)
-#if !(KMP_COMPILER_ICX && KMP_32_BIT_ARCH)
+#if !KMP_32_BIT_ARCH
 #pragma intrinsic(InterlockedExchange64)
 #endif
 #endif