C6011 warning from WIL header file

[davidmatson]

See #124 for core repro steps. To repro this case, do:

#include <wil/result.h>

In result.h, there are two lines that trigger warnings such as this one:
C6011: Dereferencing NULL pointer 'Temp_value_#7840'. ...

[jonwis]

The analyzer didn't like this:

wil/include/wil/result.h

Lines 409 to 412 in adae42b

	Node *pNew = reinterpret_cast<Node *>(details::ProcessHeapAlloc(0, sizeof(Node)));
	if (pNew != nullptr)
	{
	new(pNew)Node{ threadId };

The null check is right there, so this looks like a false positive. This makes the analzyer happy:

if (auto pNewRaw = details::ProcessHeapAlloc(0, sizeof(Node)))
{
    auto pNew = new (pNewRaw) Node{ threadId };