fix: handle two invalid VirtualAlloc/Free edge cases correctly (#445)

Fixes #421 

Ensures sogen handles two edge cases correctly:

- VirtualAlloc with size 0 and invalid flags now returns
STATUS_INVALID_PARAMETER instead of terminating emulation with an
exception.
- VirtualFree with an invalid free_type now fails cleanly, as per
Windows behavior.

Using test code from #421  before change:

Executing syscall: NtAllocateVirtualMemory (0x18) at 0x180162bb2 via
0x103858074 (KernelBase.dll)
Syscall threw an exception: 18 (0x180162bb2) - Unsupported allocation
type!
Emulation terminated without status!

After:

Executing function: kernel32.dll - VirtualAlloc (0x103703c90) via
(0x14000119a) Valloc.exe
Executing syscall: NtAllocateVirtualMemory (0x18) at 0x180162bb2 via
0x103858074 (KernelBase.dll)
Executing function: kernel32.dll - GetLastError (0x1036e8640) via
(0x1400011a5) Valloc.exe

Terminating normally:

Emulation terminated with status: 0

src/windows-emulator/syscalls/memory.cpp

@@ -181,6 +181,12 @@ namespace syscalls
         }
 
         auto allocation_bytes = bytes_to_allocate.read();
+
+        if (allocation_bytes == 0)
+        {
+            return STATUS_INVALID_PARAMETER;
+        }
+
         allocation_bytes = page_align_up(allocation_bytes);
         bytes_to_allocate.write(allocation_bytes);
 
@@ -244,6 +250,11 @@ namespace syscalls
             return STATUS_NOT_SUPPORTED;
         }
 
+        if (free_type == 0)
+        {
+            return STATUS_INVALID_PARAMETER;
+        }
+
         const auto allocation_base = base_address.read();
         const auto allocation_size = bytes_to_allocate.read();