PGO fails with "cannot guarantee tail call due to mismatched varargs"

[akaStiX]

When compiling Unreal Engine based project with PGO and LTO we get this error:

cannot guarantee tail call due to mismatched varargs
  musttail call void @"?TimerUpdate@UDataRegistry@@MEAAXXZ"(ptr noundef %0, ...) #51, !dbg !44172
LLVM ERROR: Broken module found, compilation aborted!
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Exception Code: 0xC000001D
 #0 0x00007ff79d18f7f6 xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x210f7f6)
 #1 0x00007ffe29b3bab4 (C:\Windows\System32\ucrtbase.dll+0x7bab4)
 #2 0x00007ffe29b3ca81 (C:\Windows\System32\ucrtbase.dll+0x7ca81)
 #3 0x00007ff79d191c95 xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x2111c95)
 #4 0x00007ff79d0ff7a4 xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x207f7a4)
 #5 0x00007ff79d2bbf6c xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x223bf6c)
 #6 0x00007ff79d26324a xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x21e324a)
 #7 0x00007ff79d29b199 xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x221b199)
 #8 0x00007ff79d25c828 xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x21dc828)
 #9 0x00007ff79d25fb72 xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x21dfb72)
#10 0x00007ff79d1dfb6a xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x215fb6a)
#11 0x00007ff79d1df1f3 xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x215f1f3)
#12 0x00007ff79d1dec66 xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x215ec66)
#13 0x00007ff79d358a0e xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x22d8a0e)
#14 0x00007ff79d358e91 xmlLinkGetData (d:\build\AutoSDK\Sync\HostWin64\Win64\LLVM\18.1.8\bin\lld-link.exe+0x22d8e91)
#15 0x00007ffe29ae6b4c (C:\Windows\System32\ucrtbase.dll+0x26b4c)
#16 0x00007ffe2b284de0 (C:\Windows\System32\KERNEL32.DLL+0x14de0)
#17 0x00007ffe2c2dec4b (C:\Windows\SYSTEM32\ntdll.dll+0x7ec4b)

Here's the code:

class UDataRegistry : public UObject
{
	virtual void TimerUpdate();
}

class UDataRegistrySource : public UObject
{
	virtual void TimerUpdate();
}

// please note that the class UObject doesn't have TimerUpdate method

void UDataRegistry::TimerUpdate()
{
	float CurrentTime = GetCurrentTime();

	for (int32 i = 0; i < RuntimeSources.Num(); i++)
	{
		UDataRegistrySource* Source = RuntimeSources[i];
		if (Source)
		{
			Source->TimerUpdate(CurrentTime, TimerUpdateFrequency);
		}
	}
}

For some reason LLVM toolchain assumes that it's safe to add musttail optimization to a Source->TimerUpdate, albeit this call clearly doesn't qualify for it.

Seems to be introduced by this change 0b2473936d3660ad and without it, llvm would silently produce bogus code