SWDEV-558848 - Update thunk interface signature for vmm enablement (#2259)

Co-authored-by: Rahul Manocha <rmanocha@amd.com>

projects/rocr-runtime/runtime/hsa-runtime/core/util/win/os_win.cpp

@@ -459,10 +459,13 @@ uint64_t HostTotalPhysicalMemory() {
   return totalPhys;
 }
 
-bool UnmapMemory(void* addr, size_t size) { return VirtualFree(addr, size, MEM_RELEASE) != 0; }
+bool UnmapMemory(void* addr, size_t size) { return UncommitMemory(addr, size); }
 
 bool MapMemory(void* addr, size_t size, MemProt perms, int fd [[maybe_unused]],
                uint64_t cpu_addr [[maybe_unused]]) {
+  if (perms == MEM_PROT_NONE) {
+    return true;
+  }
   DWORD OldProtect;
   return VirtualProtect(addr, size, memProtToOsProt(perms), &OldProtect) != 0;
 }