Simplify our global new/delete implementations

[jkoritzinsky]

Simplify our global overrides of new/delete and remove quite a bit of dead code.

• Stack Hashing to track allocations was a no-op as it depended on a debug-only .NET Framework component, so even when the code was enabled, it did nothing. Remove this code.
• Our debug tagging doesn't get us much now that we have AddressSanitizer runs that can accurately detect exactly when heap corruption happens. Remove it. Fixes the symptom of superpmi tool crashing with "Heap contamination detected!" #101708.
• The new(executable) variants of new are not used anywhere in the code-base and they won't be now that we support W/X.
• Since VS2012, the Windows CRT has used the exact same allocation implementation that we were using (the process heap). Just use that and don't maintain the code ourselves.

I'm confident that this fixes #101708 completely as all of the C++ standard libraries we use call malloc/free under the hood the same way we do (and macOS's libc++ in particular does).

There are two follow-up changes we can make that will allow us to fully remove our global new/delete overrides:

• Set up the StressLog OOM logging in CoreCLR using set_new_handler.
• Update CoreCLR's exception handling macros to handle std::bad_alloc and translate it to our pre-allocated OutOfMemoryException object.

I plan to explore these in future PRs.

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[jkotas]

A few questions, LGTM otherwise. Thanks!

[jkotas]

Thanks