HANGS when getting process information with NtQuerySystemInformation in post-hook

**Describe the bug**
DynamoRIO hangs when a client want to access process name if an application enumerate processes with EnumProcesses
**To Reproduce**
Steps to reproduce the behavior:
1. 1) In the sample application, create the function that enumerate processes, like this (ref: MSDN):

```
void PrintProcessNameAndID(DWORD processID)
{
WCHAR szProcessName[MAX_PATH] = L"";

// Get a handle to the process.

HANDLE hProcess = OpenProcess(PROCESS_QUERY_INFORMATION |
PROCESS_VM_READ,
FALSE, processID);

// Get the process name.

if (NULL != hProcess)
{
HMODULE hMod;
DWORD cbNeeded;

if (EnumProcessModules(hProcess, &hMod, sizeof(hMod),
&cbNeeded))
{
GetModuleBaseName(hProcess, hMod, szProcessName,
sizeof(szProcessName) / sizeof(TCHAR));
}
}

// Print the process name and identifier.

printf("%ls (PID: %u)\n", szProcessName, processID);

// Release the handle to the process.

CloseHandle(hProcess);
}

void enumprocesses_EnumProcesses() {

// Get the list of process identifiers.

DWORD aProcesses[1024], cbNeeded, cProcesses;
unsigned int i;

if (!EnumProcesses(aProcesses, sizeof(aProcesses), &cbNeeded))
{
return;
}

// Calculate how many process identifiers were returned.

cProcesses = cbNeeded / sizeof(DWORD);

// Print the name and process identifier for each process.

for (i = 0; i < cProcesses; i++)
{
if (aProcesses[i] != 0)
{
PrintProcessNameAndID(aProcesses[i]);
}
}
}
```
1.2) Then in the client hook the NtQuerySystemInformation using DR's default syscall APIs (like the code used in this sample tool: https://github.com/DynamoRIO/dynamorio/blob/master/api/samples/syscall.c)

1.3) When NtQuerySystemInformation class param equals to SystemProcessInformation, the second parameter will be of type SYSTEM_PROCESS_INFORMATION. Just make an access the UNICODE_STRING field of SYSTEM_PROCESS_INFORMATION parameter. The following code is provided for the post hook callback:
```
PSYSTEM_PROCESS_INFORMATION spi = (PSYSTEM_PROCESS_INFORMATION)spi_obj; // got from pre-hook with dr_syscall_get_param(drcontext, 1) and saved in a CLS structure in order to retrieve it in the post-hook;
while (spi->NextEntryOffset) // Loop over the list until we reach the last entry.
{
UNICODE_STRING str = *(UNICODE_STRING*)(spi + offsetof(SYSTEM_PROCESS_INFORMATION, ImageName));
}
```

1.3) Execute the application under DynamoRIO

2. Precise command line for running the application.
bin32\drrun.exe -c

4. Exact output or incorrect behavior.
It hangs and no output is showed

Please also answer these questions:
- What happens when you run without any client? Application execute normally
- What happens when you run with debug build ("-debug" flag to drrun/drconfig/drinject)? It hangs and no relevant information is showed

**Expected behavior**
Expected: DynamoRIO continues

**Versions**
- What version of DynamoRIO are you using? drrun version 9.0.19328 -- build 0
- Does the latest build from https://github.com/DynamoRIO/dynamorio/releases solve the problem? No
- What operating system version are you running on? ("Windows 10" is *not* sufficient: give the release number.) Win10 - Version 22H2 - OS build: 19045.2251
- Is your application 32-bit or 64-bit? Application is compiled for x86 with Visual studio

**Additional context**
If we enumerate processes using directly NtQuerySystemInformation, it would continue normally. It hangs only if the application uses EnumProcesses and we intercept the underlying matching syscall to access the process name.